BioWare was successful with a movie-esque presentation with ME2 but as you were saying about developers spreading themselves thin that was a game that didn't. It was very focused and intended to deliver a tight, directed experience.
It didn't try to spread its budget over vast zones and it also only had two versions of the same protagonist.
Exactly. Not to mention squads were smaller (only three member teams instead of DA's four), as well as less romances, less dialgoue and less overall time after recruitment, since that was the main plot for most of the game (example - Legion is recruited literally right before the final story arc begins). I didn't like ME2's "on the tracks" presentation as much as ME1's more wider affair, but it certainly kept scope creep down, I'm sure.
For any flaw that someone can find with DA:I, being overly ambitious probably can easily be traced back to the culprit - tons of customization, hugely open world design, developing for five platforms with widely varying levels of technology, utilizing a new engine not optimized for RPGs for the first time (as well as developing all the tools for it)... these things and so many more are monumental tasks and forget some of the other things Bioware did or tried to do (more in-depth crafting system, return of the overhead camera, reactive environments to things like hunting, etc.).
It really shows that Bioware really tried to tackle far too much with far too little. And I think TW3 in a way proves that, with its seemingly much more polished product but with its much more focused approach.