Being old doesn't mean good. From my experience, using j2ee or spring to make a web app is grossly overcomplicated (I have heard of but not yet used spring boot). Asp.net is fine but anyone who is paying $$ for that is probably a dumbass
From my experience it still offers more performance than anything based on JavaScript, or scripting language du jour.
And while other AOT compiled languages might offer a little bit more performance, they lack in tooling and libraries.
Still happily using JEE/Spring/ASP.NET + VanillaJS in what concerns webdev projects.