There are efforts to ensure that important workloads like ASP.NET Core work with it well. Due to AOT nature it's often not possible to make it require just a build argument switch, but it is still fairly easy nonetheless, in 90% of situations having to do with switching from reflection to source generation (like in the case of System.Text.Json) or solving statically not-analyzable patters of reflection (AOT supports reflection, just not emitting new code in runtime since there's no JIT!).

Well-written libraries that do not use reflection to generate new code in runtime do not require any changes and "just work". A lot of new code shipped is now written with Native AOT in mind to be compatible (with some exceptions, looking at you, SemanticKernel).