Have you tried Photopea? Photopea can also open PSD files, and it runs entirely in a browser so it's suitable for using on a Chromebook.

https://www.photopea.com/

GIMP is a useable FOSS alternative but sucks when compared to Photoshop if you're using it professionally

with all the updates gimp has been churning out lately, do you know if anyone has done a feature comparison of how far exactly is gimp from photoshop? time or features

https://www.gimp.org/news/2020/12/25/gimp-2-99-4-released/

The biggest thing missing is non destructive editing (eg adjustment layers). It's coming in GIMP 3.2 sometime in the future.

So theoretically in the next 2 years or whatever, this big feature and many smaller ones will come to gimp. Still how long before mass adoption would start because as you mentioned the biggest hurdle?

Are they ever going to change the interface, or make an extension, that will allow people leaving Photoshop to easily use it?

I think out of fear of making it seem a Photoshop clone they go too far in doing things a different way.