100%, absolutely agree on just about every point.
DS1 is master class horror gaming. It's truly Alien to DS2's Aliens, which ramped up the conflict, more numbers but still contained.
DS3 doesn't really fit the Alien Series comparison. I'd say Alien: Resurrection to be mean but I don't think that fits, either. It's just off.
It should have gone Alien, then Aliens, then a combination of Aliens and The Thing. Actionized but contained and dripping with paranoia.