> that they have to objectively ruin the site for everyone using it. See the API changes and killing off of third party apps.

Third party app users were a very small but vocal minority. The API changes didn't drop their traffic at all. In fact, it's only gone up since then.

The datacenter IP address blocks aren't just for scrapers, it's an anti-bot measure across the board. I don't spend much time on Reddit but even the few subreddits I visited were starting to become infiltrated by obvious bot accounts doing weird karma farming operations.

Even HN routinely gets AI posting bots. It's a common technique to generate upvote rings - Make the accounts post comments so they look real enough, have the bots randomly upvote things to hide activity, and then when someone buys upvotes you have a selection of the puppet accounts upvote the targeted story. Having a lot of IP addresses and generating fake activity is key to making this work, so there's a lot of incentive to do it.