Agreed.
Arkham series is even closer I would say. The core shooting and even the art design is so different between the Mass Effects.
But Mass Effect is firstly about the Story and the gameplay second except it felt like 3 broke that rule and it also had odd continuity with your choices, sometimes fully downplaying, even ignoring the largest decisions you made such as the Councilor choice or the Collector Base choice and even the Rachni was reduced to dialogue flavor.
Somehow all the major choices that had a promised impact had zero impact and only the little choices we didn't think were going to be big actually mattered a lot in 3. Such a weird priority.
Persona 2, 2, and 3!