Likes on X are now private for nearly everyone on the platform, meaning that any public figures can now like posts without any PR backlash, as certain people have had some ramifications in the past from liking certain posts. This news was revealed back in May by a director of engineering at X. Even Elon Musk has been in hot water for the posts he has liked. Musk said that this change is an important one so that people can "like posts without getting attacked for doing so."
This feature was available in September 2023, but only for X Premium subsribers.
So no-one but the post author can now see who has liked posts. The likes tab has also been removed from profile pages and the only thing you can see now is like counts. This has however, removed a perk of paying for an X subscription. X Premium+ tier costs $16 per month and mainly focuses on removing ads and the cheapest plan, at $3 basically lets you write longer posts.