I don't think that there is quite an objective answer that can actually tell the true and full picture of why exactly we didn't changed the paradigm of the web development. I think that we can imagine it and, most of all, speculate on why certain technologies were never adapted or why people would never actually try to implement something that is actually better.
The first answer that I have is that it's an accessibility reason. All the technologies that you have mentioned are accessible. Everybody can learn, integrate, and implement and most importantly, they are fast to deploy. I think that it's also a universal language that everybody can speak. If all of a sudden everybody changes the tech stack, everybody will have just to learn a new paradigm to create websites.
Another thing that I might even consider (but this is something that is very much vague even to talk about), but I want to throw it out. I think there is a certain pride in creating so much code that it's still used even to this day, so replacing it is like saying that all my lifetime work just vanishes away. As I said before, this can actually not be the case. In the end, we are talking about things that are mostly static.
The first answer that I have is that it's an accessibility reason. All the technologies that you have mentioned are accessible. Everybody can learn, integrate, and implement and most importantly, they are fast to deploy. I think that it's also a universal language that everybody can speak. If all of a sudden everybody changes the tech stack, everybody will have just to learn a new paradigm to create websites.
Another thing that I might even consider (but this is something that is very much vague even to talk about), but I want to throw it out. I think there is a certain pride in creating so much code that it's still used even to this day, so replacing it is like saying that all my lifetime work just vanishes away. As I said before, this can actually not be the case. In the end, we are talking about things that are mostly static.