Unfortunately, streaming quality isn’t as high as Blu-Ray quality would be. And also unfortunately, if it’s not released on physical disc or, at minimum, a purchaseable download (versus streaming subscriptions), working on an edit using material from it would mean that edit can’t be discussed at fanedit.org or listed on IFDb due to their extremely strict “own the source” rule.

Sadly, though, I agree - it’s unlikely that The Mandalorian will be released on physical media in the forseeable future.