There's wl-clipboard for this, has wl-copy and wl-paste commands. I've been using it on sway for years.

For Wayland I just use this:

        alias pbcopy='xsel --clipboard --input'
        alias pbpaste='xsel --clipboard --output'

I used to do the same thing on Xorg with xclip I think

Switching between macOS for job and linux for everything else, I’ve honestly never realized any difference.

I'm confused; xsel, as you might imagine from the name, is very specifically a program for manipulating the X11 selection and clipboard. So it does work on Xorg, but I'm very confused that it would work in any meaningful capacity on Wayland. Are you somehow using Xwayland?

I run KDE usually so I imagine it's xwayland.

It would be nice if you could pipe to it like pbcopy, with each invocation creating a new entry, and add support for automatically expiring old entries.