Most of the websites I've designed were built by someone else.
Now I build the ones I design, and I see how many decisions happen after the design file is done.
I wrote about what changes when one person designs and builds the site, and when that stops working: a product with a backend and user accounts needs a team. At the end there are four questions to help you choose a setup for your own project.
Do you ever come back to your old projects, and redesign them just for yourself? In the world where AI is mostly handling product design work through PRs, I enjoy solo-design evenings.