There are multiple projects built to reverse engineer their API to avoid paying the API rates(it still makes economical sense to buy a subscription for this), it was obvious that they would have to increase their bot protections at some point.

Regular captchas are easily solvable by multimodal LLMs, we're reaching a point where what's hard for software to solve is also hard for humans.

At some point they'll probably have to charge by usage instead of a flat subscription.