Try old.reddit.com - it was originally created for users who want to revert to the old desktop layout but it has an additional, unintended feature: even on mobile, it maintains the desktop layout without switching to the mobile site (note: it is not responsive so you will have to zoom - but personally I prefer zooming compared to the nagware "features" of the mobile site).

You can use i.reddit.com on mobile, it's even better.

Thank you! I didn’t know that!