Who buys hyper converged hardware ? Might be a stupid question but from what I can see you end up having to add expensive compute resources just to add storage. And if you need more compute you have to add storage too.
Conventional systems you just add whichever resource you're running low on. You can also choose to add high spec compute with video support for VDI or DaaS, low spec for services and IoT, or more storage, all modular.