It's hard to see manual coding of web sites remaining a thing for much longer.
If you mean business websites, they are just about the most volatile code out there with crazy amounts of work that never stops. It's still a form of publishing after all. Every marketing decision has to filter through design agencies, legal and compliance, SEO, etc. before it gets handed off to web devs. Then the web dev has to push back when a ton of details are still wrong. Many decisions after testing are left unresolved by the time it goes live and those pages still need maintenance until its expiry.
Smaller businesses also have these problems with their websites, but with less complexity until they get more attention from the public.
Well forget social media even. Wordpress, and now Shopify have definitely eaten the personal website
A part of my mind is more convinced by the day that people don't want all this complexity and the AI nonsense might be the final straw.
By comparison, just writing the damn HTML yourself is a breeze. I get that most people don't really want to write code, but I'd compare it to cooking. You don't have to be a chef just to eat a decent meal made the way you like.
No, what's really wrong here is a lack of simple build tools and collections of stable libraries for web that don't try to lock you in. This is what pushes people to use crapware instead.
I can't find a decent pre-made pizza crust at the grocery store either, so sometimes I just order delivery instead of kneading dough.
Even including the broader definition of applications, your average application is very little manual code, being primarily third-party framework and library code with glue and business logic.