I had this very debate amongst myselves some time ago and decided to go with a CMMG AR platform that takes Glock mags. 8.5" barrel to make 45 stay subsonic. Its close to going super but doesn't quite get there. The radially delayed blow back does seem to work better than standard blow back based on my experience.
It runs old fashion 45 all day, quietly, with a suppressor. 45 stayed reasonably priced longer than all other calibers during the pandemic but its not dropping back to reasonable prices very quickly.
The CMMG is rated for 45 Super and 450SMC, which is marginally more powerful (enjoy that rabbit hole), for the hunting / defense usage. I still like the 450 SMC. It does hit hard. You can feel it.
I thought this set up gave me as many options as I could realistically get without giving up too much.
This has been a great gun for me.
I have other guns but always come back to this one. Feels good, hits things with more perceived force than 9mm (subjective, yes, I know) and is short and easy to move around with.