Well, now we are into a gameplay shortcoming.
If when a game is designed, there isn't a battlefield reason for biotics, why would you even have it in the game in battle?
On the other hand, if you make it the only way to win all your fights, people wouldn't understand why you have guns.
So biotics have to be powerful enough to be useful, as guns do, but neither can be the only way you get through a game. Otherwise, you just did a bunch of programming for nothing. Now me, I like ME1. Because nothing feels terribly awful in getting the job done. I can take Garrus and Wrex and fight my way through, or I can take even Tali and Liara and get a mission done, though it will be harder.
For all of the gameplay ME3 is given credit for, honestly, some of their powers and who has them makes no sense. In gameplay, if Liara is a regular squaddie, she should excel at something that no other biotic you worked with can do. That was supposed to be singularity. But singularity sucks in ME3. Now the only reason to take Liara becomes role-playing or personal affinity, and it gets all screwed up. If a civilian could cause enough damage with their brain in the modern era, a military would deploy them, and then make sure they got proper combat training. Even if they had little time for that training, if that person could blow things up big enough with their brain, it would still happen.
The funny thing is that, used correctly, in multiplayer mode, multiple biotics actually become a great asset, due to biotic exploding stuff. In other words, multiplayer mode makes more tactical sense than the gameplay in SP mode. This should come as no surprise as the people who worked on multiplayer mode did their job a lot better in general than the people who worked on SP mode....