I think the problem with bespoke frameworks is that many career driven developers won't want to become a specialist in proprietary tools that won't transfer. Ho

I think the problem with bespoke frameworks is that many career driven developers won't want to become a specialist in proprietary tools that won't transfer. However... I have this strong suspicion that most projects that use something like React don't really need it. Like, if you're creating something that actually acts like an application and data might be shown in many places it makes a lot of sense, but for something that's just displaying data from a db on a page hit it can be massive overkill.