Agree about the generic feeling of filler explained by the op. To me it stretched on planets as well, making them all feel pretty similar, kill and reward, fetch and reward, scan 3 times this, destroy 3 times that etc. My first playthrough was very throrough because I was evaluating the game, trying to find things that would appease me, and I got a lot of deja vu instead. Might have lost 3h only by watching planets zooming in and out, for example. However, at the same time we think game design was bad, there will be other people who sort of enjoy that. For a company, it's easier going to what they got as the right thing, those that commute with their current design, unless the greatest majority screamed they messed up, that is.
Most Open World games are prone to be like that, I guess. Mad Max, for example, I remember going to very difficult and distant points on the map, kill mobs and the hell only to be rewarded with scraps. Rewarding in that game punished us a lot. Soon enough, you would be a bit bored by all the go here, kill that, scrap this, paint that system, because it all came to it as you were wasting your time with repetition.
But now that the game is done, hm, I'm mainly expecting them to fix the game crashing bugs; and the cosmetic stuff which seems to have an importante role to most of people. Then perhaps they will move over to the rest of the feedback? Who knows.
