A Laravel app hosted with Laravel Vapor (AWS Lambda) with a MariaDB database. Would allow me to get up and running quickly, at low cost and without having to worry about scaling for a long time.
Using Tailwind and VueJS or AlpineJS for the frontend.
The goal of the MVP is ascertaining product market fit, everything else is waste. Use what you know and optimize later. If your MVP can handle 1m calls a second, you have failed (unless it was natively supported by the framework)
The question wasn't "what is the fastest stack" or "of all stacks which is the fastest for you" but rather akin to "what is the fastest stack for you". Which is often the one that you are productive in.
It's almost always not worth learning a new stack to prototype something unless the goal is to learn the new stack.
* which stack will still be around in 1/2/5years?
* which stack Will other teammates or future devs be productive in.
I’m still searching for a very light, productive open source stack that is well accepted and if not future proof at least we’ll backed.
I have clients that still use Excel spreadsheets for their database instead of using a real one just because their data was initially stored there and they never changed. New features were added incrementally over time and it became costly to break everything for a complete rewrite. So they limp along forever because management won't let them do it right until it absolutely breaks.
But to answer your question more directly, it does happen, it's just uncommon. Where I've seen it done successfully, the rewrites have been piecemeal, not all at once, so that definitely helps with the buy-in factor.