Whoever this “expert” is has ZERO credibility
He’s talking about replacing brake PADS on drums
Hello . . . ?!
You’re licked and need to just admit it AGAIN
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That list ignores the two reasons I see again and again when I research why drum brakes are still used on trucks: cost and habit/parts inventory (related to cost). There are a few other plusses for trucks, but those two are always at the top of the list. Drum brakes are ‘good enough’ for trucks, and they’re cheaper (but that advantage is shrinking). And repair shops are equipped and stocked to work on them, as they have been for decades. In the cut throat trucking world, with razor thin profit margins, cost, not performance, is king.
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You missed a few other disadvantages - either you just don’t know or it was done on purpose.
. Disc brakes are a much simpler design and thus less parts to fail.
. Drum brakes need to be adjusted. Not always does the auto adjust system work. It’s not that difficult to get things out of alignment and the auto-adjust doesn’t work. Most I’ve worked on the parking brake adjusts the drum brakes. There’s also a trend for one side to adjust more than the other.
. Longer break-in period. Much longer than disc brakes.
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Look at the rust on that disc. Its rotting away. Just like a car does when it sits for a little while.
All of this is solidifying my statements about drum brakes, especially for trailers that tend to sit alot.
Rust burns off once the brakes are used, it is only surface rust, no where close to rotting away…
The discussion is about drums making a come back on cars, and you keep making arguments about semis and now trailers…
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Yeah…50 or 60 years from now that rotor will need to be replaced if it just sits there. Along with the rest of the trailer. 
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Its a simple fact that the brake shoes typically make contact with about 80 percent of the drum. Most pads only make contact with 30 percent of the disc mostly due to limitations of the caliper.
Disc brakes are wasteful. Drum brakes are more space efficient, more mechanically efficient.
Disc brakes shed heat better in many cases.
Drum brakes are less likely to warp.
Drum brakes are a strong brake. A brake that is in it for the long haul.
Discs are a showy, flamboyant brake that are good for a fast ride.
Thanks for concisely listing all the cockeyed ideas you think are important. Good laugh.
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So “Disc brakes shed heat better than drums” is a cockeyed statement?
All but one.
I tried to stay out of this, but could not prevent myself from replying.
Fast rides like trains and the, now retired, Space Shuttles.
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The speed of water molecules in air is about 1000 MPH. They are so small that the space between the drum and the backing plate is a negligible impediment to moisture entering the brake drum. This argument just doesn’t hold water. 
PART 2:
The trailer as well as the brake rotors are from 2016 and has always been stored out in the open, so not bad for “It’s rotting away”…
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For anyone interested in an actual comparison of the pros and cons of disc vs. drum brakes on trucks, here is a good one:
Drum Brakes vs. Disc Brakes: What’s the Difference? | Rush Truck Centers
Their summary repeats everything we all (except one) have said, discs stop better, drums can be cheaper:
Key Takeaways
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Drum brakes are more economical to produce and repair, offer long service intervals and are lower maintenance due to their enclosed design. However, they’re prone to overheating (brake fade), moisture-related issues and more complex repairs.
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Air disc brakes offer 17–33% shorter stopping distances, better heat dissipation, self-adjusting capabilities, more consistent performance in wet conditions and they’re easy to service.
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Vocational trucks with frequent braking benefit most from disc brakes, while drum brakes remain a practical, cost-effective option for long-haul trucking with less frequent stops. Ultimately, factors such as driving habits, operating conditions, stopping distance requirements and maintenance preferences should guide your decision.
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What does it mean - REPAIR? Is this referring to replacing the shoes when worn out? If so then I completely disagree with that. Disc brakes are significantly easier. I’ve found that everything is easier to do on disc brakes. I can replace the rotor. caliper and pads on disc brakes faster than I can just replace the shoes on drum brakes.
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Yeah, confusing comment, especially given what they say about discs. Maybe just a comment about parts being cheaper?
The ONLY thing I thought of was - Shoes can be relined (repair). Pads you just throw away.
Economical: Drum brake systems contain much more friction material and a greater swept area than disc brakes, results in a longer service life between replacements.
Longer service life is an advantage for commercial truck use, with the compromise of drum brakes are less efficient than disc brakes.
BTW, we were usually paid the same labor for drum and disc brake replacements. It shouldn’t take more than a few minutes (per wheel) to remove brake shoes, clean and lubricate the backing plate and install new shoes. Time is lost when replacing drum brakes while waiting for a hardware kit to replace broken springs.
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There’s no significant difference in the time spent relining disc or drum brakes. Replace pads and clean/lube caliper slides or replace shoes and clean/lube backing plate and adjuster, depending on the vehicle the shoes may be faster. If you’re replacing calipers or cylinders that may add a few minutes, but more time will be spent bleeding the system than replacing parts.
Brake shoes used to cost less than pads, but the savings would not be significant unless you’re maintaining a fleet. For the DIY crowd, what’s the difference if the friction for your brake job costs $35 vs $40?
One thing that has gotten expensive is the iron. Have you priced out drums and rotors lately?