As a generalization:
- For DI engines, they are certainly a worthwhile consideration. Plenty of YT videos out there; check out the one by Engineering Explained - it's detailed and very informational.
- For PFI engines, it's not really a necessity by any means. It can help but the improvements would be much smaller relative to DI systems.
I'll add this caveat ... each engine brand/type/series has pros and cons. My new 2023 MX-5 is a DI only engine and I thought it would greatly benefit from a catch-can. So I got a really nice one; made near me in Indy (very high quality unit and looks "stock" when installed). I've run it for 6k miles now, and have caught diddly squat. Why? Because apparently the little 2.0L in the MX-5 has a very good block-mounted PCV system, and so there's just not a lot of vapors making their way up to the intake. A catch-can can only "catch" what is present, after all.
My point is that if the DI system in a vehicle is paired with a very effective PCV system, you're maybe not going to see a lot caught in the can. But for systems which seem to puke a lot up to the intake, I think they are a good idea.