Also Room EQ (https://mathaudio.com/room-eq.htm) and REW (https://www.roomeqwizard.com/)

Shammy. You cannot truly correct for a room without actually changing the room itself.

You don't have to "truly" correct for the room for EQ/calibration to be worthwhile - you just have to make it sound better than it did. I've used the built-in calibration in my WIIM Pro and it subjectively made a massive improvement.

I used to be in-principle anti-EQ, but the AutoEQ project for headphones completely changed my opinion (though obviously headphones are far easier to EQ).