so bass traps in corners do nothing, it seems we have been fooled. or are being fooled.

So the tiny little gray or blue "triangle" corner traps (popular a while ago) always made me chuckle.

Those were not intended for and were never promoted to be bass traps

and I’m not promoting these nor commenting on their effectiveness, and you may well be correct,  but comments like below with nothing to back them up are basically worthless conjecture

And those tiny little "acoustic resonators" (often sold at very high price) are unlikely to do anything but placebo.

https://trackingangle.com/equipment/asc-tube-traps-for-life

here's another take on it