While it's true that VST3 may work seamlessly for some users, it's important to recognize that the decision to discontinue older architectures isn't solely based on support needs. Plugin formats, once established, typically require minimal to none ongoing support. However, the discontinuation often stems from strategic decisions by developers rather than technical necessity.
Don’t get me wrong, I’m using VST3 myself, but I don’t see anything wrong for the VST 2.4 format to be used in plugins and supported on other DAWs which aren’t developed by Steinberg.