I think Starfield and the Mass Effect series are different enough to make this not a fair comparison.
Mass Effect is all about the story and Shepard playing his/her own little role in that story, while Starfield is about exploration, like every other Bethesda title. Mass Effect excels in weaving a nice story and world, and to a lesser extent, Combat. I wouldn't really call it an 'exploration focused' game, nor does it excel in RPG mechanics to the level that Dragon Age does. For Starfield the focus is on exploration, first and foremost, combat is secondary, and the story (whether or not you find it engaging, i do) is tertiary. And the exploration in Starfield is still great compared to most other space games (yes the constant loading screens hamper the flow).
The space-saga setting and RPG elements make it an easy comparison at surface level, but if you go in depth, they are very different games. It is like comparing Dragon Age and Skyrim. Dragon Age was an excellent CRPG with a focused story, while Skyrim is an explorer's playground.
Shitting on starfield may be the cool thing to do right now, but credit where credit is due. The feeling of exploring a vast world (or rather, a vast galaxy) is created very well in Starfield. It is good looking and polished, and the best parts of it work really well i.e the moment-to-moment exploration, supported by subtle world building and some great side quests and random encounters.
Now having said all that, all games across every genre still compete with each other for the player's time and money. And i think Starfield is not quite at the level of value as the Mass Effect Trilogy yet. Maybe, with mods, it will get there.