A ToC is more important than a list and should build a graph to other parts of your document. If the only agreement we have is that something is a list, then we've reduced the semantic meaning of a list to the question of whether we should have visual signifiers like bullet points or numbers.
I want the niceness of Wikipedia generalized elsewhere but abstracted by my client or browser. The more we agree on the precise meaning of elements, the more we are empowered to programatically redesign or interact with content.
Screen readers actually do generate a couple of different things that you could consider a ToC from the semantic meaning of various tags. If you structure your document properly, it's not a terribly difficult task for the browser to generate it. Apple showed that Safari 18's reader mode is going to have one, actually.
I want the niceness of Wikipedia generalized elsewhere but abstracted by my client or browser. The more we agree on the precise meaning of elements, the more we are empowered to programatically redesign or interact with content.