For me personally I think a big chunk of why FOSS alternatives seem “bad” is because you don’t know how to use them (yet). I spend decades of familiarising myself with all the horrendous fucking “quirks” and bad UX and other stuff of Adobe software and internalsing all that bullshit. When Inkscape had different “quirks” (= ways of doing things) of course it’s easy to dismiss it as “bad”.
And yes, some software that is mostly made by a bunch of volunteers for free can’t feature-compete with a multi-million company, surprise.
I think it would be more interesting to find out why Adobe software is still so abysmal after they’ve probably thrown hundreds of millions of dollars on it. I recently watched my brother work on a complex project with Premiere and it was almost non-functional, quite fascinating, actually.