Saw one where powercreep is considered unhealthy ...if you played a competitive card game without power creep you'd quit because the first meta would be the only meta. Controlled power creep is healthy for game longevity.
That doesn't mean that's the only way to be a good game, and I don't necessarily have an issue with powercreep. If it's mild and expected, powercreep can also be a way to handicap... If you're introducing new people to a game, maybe you let them use current cards and you use 5 year old cards (or whatever), they get to practice with current cards, get to experience old cards, you get some nostalgia from your old decks, and you don't have to sandbag, because they've got an advantage.
Using Arknights an an example it has a power creep as 5/10 despite being possible to clear current endgame with only 4* operators, which are essentially guaranteed as a free to play.And the bulk of them being added at the games release.