Earlier quoted context omitted.
You write some simple HTML, style it with CSS, and write vanilla JS for the parts that need it, and everything feels solid. Bootstrap + jQuery on the front end, Flask or similar with CherryPy on the backend. SQLite or Postgres if you need it. That will handle 99.9% of websites, it will be cheap and easy to develop and host, and deliver a great experience to the end user.
> Bootstrap + jQuery on the front end Why? CSS can do layout with grids and flexboxes just fine, while es6 plus the modern browser api are as ergonomic as jquery. Why pull these dependencies from a decade ago?
I never bothered to learn CSS is why. Bootstrap looks good and consistent with what users expect and requires almost zero effort to use.