In some cases, depending on driving habits, it's possible to need an induction cleaning at 20k miles. If the car appears to be running fine, then you don't need it.
This also applies to fuel injector cleaning. If it runs fine it's not needed.
Just a tip here. If there is ever even a hint of a fuel injector problem you will notice this at idle.
An injector acting up a little will cause a rough idle to some degree, a stumble now and then at idle, and possibly a hesitation when taking off from a stop.
These aervices are sold as money makers. While it can be considered helpful it is not necessary and even doing this every 20k miles will not extend the life of the car.
Regular oil changes, coolant changes, not driving the car for ages with an overheating problem or a Check Engine Light illuminated, etc. is what determines the life of the car.
Short of someone plowing into it or the car getting eaten by rust weevils in Minnesota of course.