The only downside to the battery booster is you need to charge it monthly. If you don’t when you are stranded your booster could be discharges and useless too. The booster may have difficultly starting a cold motor on a very cold winter morning.
Cheap jumper cables are pretty much worthless. If you get a set spend some extra bucks for better quality and capacity.
I have both so this isn’t an either or question. If you have room on your trip(s) to carry both do so. If not, then make a choice as you pack. I’ve used the booster much more often to start my boat. I find the booster handy and use it more often than the cables.