Earlier, merchants could save the details, and this ability leads to massive amounts of fraud and theft (see US right now).
Then only regulated payment aggregators could save them, and issue a token to the merchants. Stealing the token wasn’t too helpful because you couldn’t grab the money, the token was tied to the merchant. But this still means my card number is stored on a bunch of companies that can suddenly take whatever funds they want, and I can’t cancel these tokens.
Fast forward to 2022, where only the issuer I got my card from can give out tokens - so I can now see a list of every single merchant who has access to my card tokens, and I can cancel them whenever I want.
So the functionality is not going away, it’s moving to another part of the regulated system that’s more in the control of the consumer.
As a person I welcome the move (no more struggling to understand card charges or pleading with companies to cancel my subscriptions). As a developer it’s more work to implement the new system, but it’s not much more work than the old one. Projects using Stripe or Razorpay will get the new system with no changes.