I'm curios if seasoned vaper's at 20 or 30 watts change about their juice or if they stick with the same MG...?
I can't speak for everyone, but for many, it's more about the design of the atomizer and potential flavor goals than it is the power applied... although, in many cases, they can (and with unregulated mech mods - must) go hand in hand.
Many atomizers, benefiting from a thoughtful design, are able to concentrate flavor and nicotine content more effectively than others. That performance may require a resistance value that, accordingly, requires more power.
A RDA with a net resistance of 0.5Ω at 4v would require 32w/8a. The primary goal would not necessarily be to obtain those power values, but rather to obtain the flavor/vapor benefits of a RDA with 0.5Ω resistance.
A typical tank RBA like a Kayfun, might be found with a (popular) coil resistance of 0.8~1.2Ω. Not so we can crank power up to 20 plus watts... but because flavor, with many juices, may be optimized at those resistances. Again, power being simply a necessity rather than the goal.