Fold into Paizo.

Honestly there isn’t anything in D&D worth saving that hasn’t been done better elsewhere. Making it good requires rewriting the system and lore from the ground up - they tried with 4e, but didn’t have the time to complete either so all the classes functioned like casters and the setting was literally lifeless. 5e has just been a “best of” collection, dressing up like old favourites and reissuing classic adventures.
PF2e alone is everything 3.x, 4e, and 5e wanted to be, has a massively detailed and extensive setting that isn’t filled with cliches and problematic elements, and has only had to undergo minor canon changes rather than universe changing events between editions. It has accessibility, diversity, and inclusion out the wazoo, heavily supports the player community, and a steady supply of high quality adventures. PF2e fits the exact same niche as D&D, while being an all around improvement, even on price.