I bought Elite Dangerous, played it loads, really enjoyed it. One day, they said 'we're no longer supporting MacOS'. Fine, I thought... except it turns out even their single player mode needs to be online to work, and they were disabling that as well.

No refunds, no apologies, just a game I'd paid 50 dollars for suddenly didn't work any more. Ultimately, still value for money given how many hours I'd ploughed into it before they broke it, but yeah, I think twice now about that kind of purchase.