On Ubuntu there is a snap available shipping Emacs 28 including native compilation turned on:

https://github.com/alexmurray/emacs-snap

I am using it as a daily driver for months already without issues so far.

Maybe the buntus are lagging behind in Emacs. I think most others have 28 in their releases.

On Windows it's very easy:

Download from https://github.com/kiennq/emacs-build/releases

Unzip into a folder of your liking, C:\Users\<username>\AppData\Local\Emacs would be a sensible start

Debian has 28 in unstable, looks like there are some issues to fix before it can reach bookworm.

https://qa.debian.org/excuses.php?package=emacs

I used to build my own emacs, but after being annoyed with it breaking after each upgrade on unstable, I use the emacs-snapshot repo on http://emacs.secretsauce.net/ with bleeding edge packages for Debian sid.

If you're on a distro which doesn't have Emacs 28+, one option is to pick it up from guix.

What functionality in 28 do you need that 27 lacks? (curious)

libgccjit for faster elisp

I think that native JSON support is also in 28. It helps lsp.

That was added in 27.