I've recently started using the new .NET 6 templates and honestly I don't miss the OOP boilerplate. Yes it's a bit of a shock at first, but you quickly realize that having your ASP.NET Core startup code split into two files and three functions has no real-world benefit.

I'll still be using traditional controllers for my endpoints, however the syntactic sugar in C# 10 does improve the experience by reducing nesting and noise in general (file-scoped namespaces & implicit global usings).

Overall I'm pretty happy with it.