It feels to me like hobbies are only relevant on entry jobs or for younger hires who don't really have a fully fleshed out CV yet.

When you have a bit of experience and apply for more advanced positions, you have better things to discuss in an interview and certainly don't have enough CV space to describe your hobbies.

At best, you may spend a minute or two saying what you enjoy outside work if the recruiter goes for the culture fit angle, but that's about it.