SC have value in flopping multiple draws. If you flop an open ended straight draw you have 8 outs. If you flop a flush draw, you have 9 outs. But with suited connectors you can also flop combo OESD's and FD's, which can give you 15 outs. This allows your hand to have a 60% chance of completing either draw and makes your hand a favorite against any TP or 2pr hand on the flop. Flopping things like a gutshot straight draw and FD gives you 12 outs (48%) which is pretty much a coin flip, and if there is any money in the pot, gives you enough equity to get your money in.

You cannot be concerned about flush over flushes, since they don't happen as much as you think, not on a 3 flush board anyway. If the board is 4 to a suit, you have something to worry about.