If your goal is to build a product for your own startup business, the best stack is Google Forms + Google Sheets. Then getting on the phone and selling.

If your goal is to learn the marketable skill of building web apps in 2023, you can't go wrong with Typescript on the front and back end with NextJs (aka React, aka one of the most in-demand technologies employment-wise in the industry).

If your goal is to just have some fun on then Svelte + Rust ain't a bad idea.