If you are robbing your subwoofer of power with DSP, then there must be
frequency aberrations at the listening position that need to be fixed.
Kind of sort of. Sorry to introduce nuance here.
Not all ARC is the same, not by a long shot. Early ARC attempted a flat response and it sounds awful, so I can completely see why if you heard that you'd be of the opinion it steals power. JL Audio and Dirac are examples of ARC that no longer make these fatal flaws. I encourage you to listen to them if you can.
Still, we don't have the luxury of doing everything right. We can't all have 2 subs, room treatment, and a choice of anywhere in the room to place them.
In my mind, for each listener and their home there's some combination of this that will be ideal. If you can't do all, do 2 of them. If not, resort to EQ alone.
For instance, I can't have 2 subs, and I can't pick a location. It's really 1 place or no sub. What I can do is add room treatment and EQ. Result is marvelous and much better than doing nothing.
Despite all of this nuance, ARC is still the best fastest way for a new sub user to configure the crossover, delays and levels.
Best,
Erik