I don't think these subscriptions are in any way required. That said, the company usually pays for it. If you hit a limit, you can usually extend it. You don't want your private proprietary AI account be used for work and vice versa. You should mind privileged info, etc.
Personally I use a local solution the most. Gives me more control and while it isn't as sophisticated for managing large projects like integrated solutions, I am not dependent on any provider. Vibe coded projects always end up in a horrible place and maintenance is a minefield.
Some have integrated solution with their repositories, where you can delegate some easy issues for AI to be solved. If you know what you are doing and what you can expect, this is helpful and saves some time. But there certainly are pitfalls to an AI intern. Not sure yet if such tools save time or waste it by creating issues.