I'd then spend a bit more collecting all copies of 21st century video versions - and incinerate them in a volcano. I'd end all current licensing deals, pay a team of lawyers, IT staff, and some hackers to destroy every moment of footage on video platforms, in torrents, on obscure FTP sites. I'd pay Peter Jackson to sign an agreement never to discuss Tolkien again.
And then what? I'd find someone with the highest artistic merit, who understood Tolkien's vision of fairy tales and fantasy and mythology. Live action, computer-assisted or not, brings the supernatural Tolkienian settings -- his greatest power as a writer, as vivid today as when I read them: Moria, Lothlorien, Minas Tirith and Minas Morgul, Mordor, Orthanc, Fangorn, the Paths of the Dead, etc. -- to the mundane level of what we can see. The new film(s) would have to be hand-drawn animation, which can imply and leave room for so much more in our imaginations.
But who? Old Pixar, the ones who made Ratatouille and Wall-E, might have been an excellent choice. Miyazaki is much admired; I don't see that style fitting the material, but on the other hand they might have their own vision that, let loose, would set the world on fire. Similarly, the creators of Spiderman: Across the Spider-Verse did something uniquely visionary, and possibly could make their own vision of Tolkien.
So to my point: Who? Maybe there's a video game artist? Maybe a different artist for each setting? But whatever we do, it must be art first and formost, without compromise.