After getting all the Theatrical Posters (minus Solo...it looks nice, but they style is just so different from the others) I consider my collection complete in this area. I just got them all up in my new office and they look awesome!
Yeah, the Disney streaming posters have mostly been meh, but I'm sure they're not putting a ton of effort in to them either. For the most part I still get them all and like them, although I don't like that they put dates on them.
They're more or less free, or close to free from Disney. If you link your Disney+ subscription, and scrape up all their free points throughout the year from other promos you get close to 1000 points, which will get you about 2.5 posters a year if you can get them on Wednesday Wins discounts of 400 points each.
If you ever need more points you can buy codes from DVDs on eBay for cheap too.