Are you aware of Redlib? Self-hostable frontend for Reddit aimed at privacy. I’ve never had a problem with old.reddit but Redlib has a bit of a more modern UI if that’s what you’re after. There are a bunch of public instances if you don’t want to host it.

Otherwise I’m sure you could use uMatrix to disable the tracking (can’t give detailed instructions sorry), but I’d argue hitting Reddit’s domain at all is already less than ideal if you’re trying not to be tracked.

I’m on Wayland these days, but if you happen to be using X11 this is the homebrew solution I used to use:

xdotool type --delay 50 "$(xclip -o -sel c)"

The --delay argument specifies the delay in milliseconds between keystrokes; if you go too low on that it tends to break things.

Interested to see what solrize comes up with because this method definitely has drawbacks – no way to interrupt it and if you accidentally paste something large it takes a long time to finish due to the forced delays.

I’ve never really had the need for a Wayland version, but I don’t see why subbing ydotool for xdotool and wl-paste for xclip wouldn’t work.