I’ve done a 1 month MVP on each of these stacks, it’s not just the initial deployment. React is better integrated in Next, and you can get more done faster and simpler. DRF has poor async and is not an ergonomic practice in 2022, Flask requires lots else to build and maintain with weaker integration / community, and if you’re arguing why HTML templates are just as good, well, Fortune 500 and every HN startup has left it behind for good reason.