I totally agree here about how poorly RO does set up ANH events. I like the idea that sustains RO to get a deeper look into the Empire, I’m less a fan of seeing grey areas into the Rebels (because in the fantasy context of the OT, this doesn’t cope with very well).

So, I would say about RO:

on a storytelling perspective, it’s a very bad prequel, like AOTC bad (yeah, that bad);
on a vibe perspective, it gets it right most of the time, especially on the Empire side;
on the visual perspective, it elegandly connects the PT to the OT, using modern filmmaking and a sense of grandeur that mesh very well with ANH.

I can enjoy RO as a fun ride (not all of it, 'cause the first half is very boring and even the action packed second half has many issues, but still there are a few very good moments), but definitely not as a good prequel. The PT are very imperfect prequels as well, however they are set far enough before ANH to let my brain connect thibgs in a clearner way. Something that RO with its “five minutes before ANH” ending doesn’t allow to do, unfortunately…

That’s being said, among the 5 Disney Star Wars, I would rank it second (TLJ > RO > Solo > TROS > TFA).