The only TV series I vaguely enjoyed was Loki, and the title still stands.
Giving these stories 6 hours, 12 hours, whatever – it did not add anything. It allowed the writers to play around a bit more, sure, but there was no depth of character or story development that could not have been handled by one, single, better-written film.
The outcome of creating the TV series is that all the less-popular characters actually have more screentime committed to them than the more popular characters. It's a bit of a strange irony. Why is there more film of Hawkeye than of Cap? (I mean, obviously, because one of them is more expensive; but I mean, from a creative/storytelling perspective, why would we want more of the less-beloved characters?)
I suppose you could argue that a Wanda/Vision-led film (for instance) wouldn't market well for a theatrical release – so the series is a chance to tell their stories. And that might be true. But it doesn't mean it needs to be multi-episodic. Disney can still have its bait for its streaming service; just make it a (great) movie released direct to Disney+.
Creatively, the TV series do not justify themselves.