I’ve always wondered about this too. FWIW — we had a remodel done on our house, they did a great job and I was shocked at how fast they got it done. So speed doesn’t necessarily rule out quality.
What I always worry about more is: if they are just doing a flip, they probably cut every corner possible, cost-wise. I was always suspicious of quick flips just because the incentive seemed to make things look superficially good but to otherwise keep quality as low as possible.
That’s my semi-useless take; perhaps some more experienced buyers have better info.
