I know the evidence is that plenty of people are totally happy with applications running in a browser -- Office Online, Google Sheets, etc. are compelling evidence -- but I strongly prefer dedicated and native applications for something I'll be spending a lot of time using.

I'm not even necessarily blaming this on the performance difference, although that is a pertinent topic, but just the mental structure of something I'm using living in a browser tab rather than actually running on the computer.

Installable web apps would give you a workaround for that wouldn’t it?

They are still bound by the constraints of the Web.

For example WebGL 2.0 (2009 hardware), WebGPU (2015 hardware), any GPU capabilities after 2015? You ain't going to get them.