I had a one cesarean in my life--my only time I gave birth. And in order to keep my belly reasonably flat, I have to watch what I eat and do many crunches. Don't ask how many--sometimes I lose track!
There are things that exacerbate a flabby belly, though. Poor posture, sitting for prolonged periods of time without keeping tummy pulled in, constipation and gas/bloating, too. Supposedly stress does its thing, too, in making one gain belly fat.
But would I have rather had a flatter tummy and never given birth than had my cesarean? Never in a million years. My granddaughter likes my soft curves to cuddle on, too.
I don't know about a tummy tuck. I have my doubts about cosmetic surgery that involves cutting and just the anesthesia alone. I'd try everything else first--and have fun doing so. Like exercising to my fav music or including kiddies in on it.