why not a film?
I know it was originally to be a film, then Solo happened.. But its not like it'd bomb as happened with Solo..
A (decent) Obi Wan movie with Ewan and plenty force/Jedi elements and light sabre action (& a Maul rematch) would probably be as big as Rogue One. youd at least had the familiarity of the original actor back (ok not Alec but the original in alot of peoples minds who are now grown up who loved the prequels as kids)
when the standalone 'SW Story' movies were announced I think there was abit of buzz about as fans and just audiences in general were hyped with the idea of an Obi Wan movie (not so much a Solo movie wout Ford).
I bet Ewan wouldve much preferred doing a movie over a TV show