But bnce the code is written to handle it then it's there for everyone to use (though yes, billing infrastructure does requires continual upkeep) - it could even be an internal garage/passion-project/hackathon thing. Companies like Twitter want to attact "the best", and people like that will want to build products that they themselves want to use - why stop them?
Plus there might be other intangible benefits to supporting power-users: it means the power-users will talk about how great something is, and you can't buy word-of-mouth influence like that.
> Me, you, and most of engineers are in extreme minority for our willingness to pay for stuff to avoid ads.
People said the same thing about paying-for-YouTube, and yet YouTube Premium is here to stay, and I'm glad that Google was willing to experiment with the concept, and it worked - but what about all the companies that aren't willing to at-least try to find out?
A passion project is great until the passionate project flounder moves on, then it’s unmaintainable junk.
It’s kinda like how Microsoft handled easter-eggs in the 1990s (before they were banned completely around ~2003), where the egg is just another engineering feature-project, with a spec-doc, a dev timeline, a test plan, and accountability - even if the end-feature is designed to be hidden.