Do we ask if Red has retired from his Pokemon Journey? Or from the franchise in general? And you all know the answer: Of course not.
But Red's adventure is not something the franchise needs to entirely focus on. Sometimes, Red goes on an off-screen adventure. Sometimes, the story is rebooted. But no matter what, there's always going to be an adventure with Red. Same with Ash.
The question at hand is whether or not the main anime is going to retire. It's easy to continue Ash's adventures through spin-offs, movies, and manga. But a weekly series is a different matter altogether. And people should take note of that.
I suspect the reason we went to the whole world rather than sticking with Galar is because even back then, the weekly series was becoming a burden. My Hero Academia hit the anime stage in 2016 and showed animators and producers in Japan that you don't have to make a weekly series with ton of filler to capture an engaging show. In fact, it was better for the animators and audience to have a more tightly knitted show.
Journeys was experimentation of where the show should go, from a new protagonist who could potentially replace Ash to Ash being given no limits on what Pokemon he can get to a special mini-series only reserved for Amazon Prime.
And even then, the pains of weekly demand eventually caught up. The show went on various hiatus just so animators could finish up episodes in time. And also note that not all the Galar Pokemon were shown or even featured in a spotlight.