Generally, I view streaming services as the modern-day equivalent to a rental. If I like something I see via one, I'll probably go and try to get a physical copy of it.
But as you say, there are a lot of things that don't ever get a physical release, for no good reason. (Well, I'm sure there IS a reason that sounds good to someone. Probably someone in a legal department, of course.) Honestly there are more than a few things that got physical releases, but not in a proper way. I'm just going to put this one in particular out there... My Little Pony: Friendship is Magic. Show has always aired on an HD channel, but they have only ever put the show on DVD... so an SD format. I still buy the DVD season box sets, but I would love a proper physical HD release. Now, like... in the case of Code Lyoko, I imagine a DVD release would make sense, since it was airing when HD was still a "luxury" and fairly sure the show itself wasn't produced as an HD program (I may be mistaken, it's been aaaaages since I've seen it.)
Anyway... just gonna say one thing about the Pokemon movies. I honestly think that the movies were the best part of the anime for a long time. I don't know when the quality dropped off, but I know for certain the Diancie movie was about the point where I realized they weren't trying very hard anymore.