It's pretty easy actually - most open source software fits the bill. Quality software can be pretty cheap to make per user.

The only problem is services where hosting costs need to be paid somehow and network effects mean that for-profit competition will win the market even if the product is inevitably enshittified. Doesn't matter how good your open and community funded event platform is if Apple and Facebook can afford to shove their solution in front of everyone you want to interact with.

What open source software is a "nice thing"? We're talking about high quality user experience here. I don't think it's controversial to say that's vanishingly rare in OSS.

Actually it's proprietary software that's more likely to be full of anti-patterns and flows designed in the interest of the corporation rather than the user while advanced functionality is missing because it might confuse the lowest common denominator user. Looking flashy and retard-safe design does not make a high quality user experience.