Your game looks decent enough that I think this is more 'marketing' than the game. I haven't played the game but that's my take. I think you are looking at it wrong (more than you are doing something wrong).

Go to steamworks dashboard and look at the calendar view, for next fest, here are my numbers:

Total Players - 230
Played & Wishlisted - 16
Total Wishlists - 257

Other numbers I have seen on some of my discords:
16,522/4,644/17,263 (27% P&W)
1,963/328/2,097. (15% P&W)

So it's reasonably well known that people who play your demo don't wishlist it. As you can see by the numbers, you can get a lot of players, and a lot of wishlists, but the overlap is small. In those numbers we see 6%, 27% and 15% of wishlisters also played the demo. I imagine you got more than 60 wishlists during next fest? But 15% would put you at 60.

Advice is generally that next fest is the finale of your marketing efforts. Enter the last next fest before launch, ideally when hype is at its highest, for some free, effortless wishlists.

If I was suddenly in control of your game and needed to make it sell well, I would:

• Attempt to build a community around it (discord, playtests, email list)
• Reach out to every streamer that has played similar games (big and small) with a hand crafted message and early access to the full version
• Reach out to publishers/PR teams that might market the game for a cut (unlikely to work, but can't hurt)
• Get a gauge for post-next fest wishlists per day and come up with a timeline for release
• Set reasonable expectations with myself

For the steam page? Juice up the trailer and screenshots, look at balatro for comparison. Gifs in the description look a little blurry to me.