> we give up on the tools that companies use. UX, user research, graphic design, marketing and similar roles are pretty absent from these communities

Some of the bigger open source communities, like GNOME, do some amount of these things. But I think very few people are excited enough about user studies or marketing to do them as a hobby, unlike writing code. It's hard to see how you could beat Google/Apple/Microsoft at their own game like this without a lot of money. Red Hat is probably the biggest company that might be interested in this, but still about 2 orders of magnitude smaller than the giants.