This is either absolute approval of the power of a 486 (with turbo speed no less!), or some slight judgement over my Neon Genesis Evangelion obsession...
For desktop use I would recommend Raspberry Pi OS too - if it is going to be for desktop use, I found that using the option to boot directly from an SSD (if available) gives it a bit of extra smoothness.
Lucky you with that Pi4. I think the official OS will be the most comfortable for general desktop use. If possible, boot from SSD (never USB) because microSD cards can occasionally crap out.
A few years ago I had success running Ubuntu MATE on my pi (PI 2 Model B), all I did was writing, browsing and some emulation gaming but it ran pretty well.