When you think about it, with roster spots for 1B, Corner Infield, and some sort of utility/DH slot, you can essentially start three first basemen every day. If you plan your draft well, and know where the emerging (or returning from injury) first basemen are in the draft, you could draft 80 HRs at 1B alone. That gives you a lot of flexibility in finding steals or focusing on higher batting averages at other positions.
There’s a lot to like at first base, but like I said injuries and time-share situations emerge, so the attentive owner who checks pitching matchups each day will be able to roster (and stream) more first basemen. And, if you have, for example, four good first basemen on your roster there will be at least a couple of teams struggling at a position that should be a sure thing.