What’s the best long term weed preventer besides weed paper?

You could try newspaper. I've seen that recommended several times in the forum here. It works like weed paper, but is much more cost effective and environmentally friendly (yay recycling). Good luck!

Yes, we've done newspaper with a layer of mulch over top for aesthetics. Use a lot of newspaper if you choose this option, multiple layers as it breaks down. Landscape fabric definitely lasts longer, but you might get 2 years out of the newsprint + mulch technique.

I use cardboard sometimes. It's nice and thick, but eventually decomposes (better for the environment in the long run.)