The best card game out there right now is the Digimon tcg. The games are fast and they simply do not do box chaff. And of all the current tcgs, it's got the biggest actual playerbase outside of Yu-Gi-Oh.
Alternatively, the Pokemon card game is fully owned by Nintendo now. They aren't doing a great job with it IMHO, but a lot of people do collect the cards.
There's a digital TCG which is almost identical to MTG called Eternal. It's free on Steam and mobile. Recommend you check it out and see if you like it. I personally think it makes much better use of the digital medium than MTG arena, which often felt clunky due to the way the rules had to be ported from tabletop.
If it's under a CC license you can literally publish it yourself with a few things tacked on. That's what creative commons does. It's basically public domain at that point.