As in the actual point of the quest. There was a lot more depth and variety in the quests in ME1. In ME2, most of the quests were cookie cutter, very brief, and weren't interesting in the slightest. In fact, the side missions in ME2 largely felt out of place because they didn't make sense with the rest of the game. Why was Shepard and team wasting time saving quarians from a wave of varren attacks when he/she was supposed to be stopping the Collector's (actual quest in ME2)? Whereas in ME1, you may come across a bunker filled with husks because human scientists who were analyzing an uncharted world happened to unlock ancient reaper technology they didn't understand (actual quest in ME1). Not only did the quests in ME1 make more sense, but they actually had depth and enriched the experience.
Why was Shepard wasting time with any sidequest in ME1 when (s)he was in a race against time to track down Saren? The same argument applies to pretty much all of Biowares games to be honest. Every now and then sidequests feel natural (BG1/2, DA2) but largely they feel so inconsequential next to your primary objective they break immersion.
As for the "actual content" I have to disagree. In ME2 you are tracking down prothean artifacts, mercenary bases, saving a crashing ship, finding hidden stashes, investigating weather control, saving a colony from a missile strike etc. They experimented with different gameplay mechanisms like weather obscured vision, timers, vastly different layouts etc. I personally feel the N7 missions in ME2 get kind of a bad and undeserved rep, some are pretty decent.