Read through this thread and see if any of the things mentioned there are important to you.
If not, it's been reported that Fusion 360 is very performant on the new M1 chip even running in Rosetta2.
Complex Boolean operations using mesh objects are much slower with the M chip in emulated mode compared to a Mac with intel chip!
Are they still meshes, or did you convert them into solid bodies (BRep) to conduct the boolean operation?