You know why PHP is still around? Because it's fucking simple.
The levels of abstraction in Web Frameworks like React/Angular or ASP.NET Core is a little silly. You have to navigate through 4-5 files of logic before you actually get to the rendering of a page.
PHP?
<?php echo "Hello World!"; ?>
If dotnet could give me a syntax and framework as simple as PHP, I think it'd dominate. Just one file (index.cs), not a zillion files and boilerplate.