You're not missing out feature-wise, no. Helm is the original kitchen sink power tool on this front. The Vertico-stack is interesting for different reasons, like simplicity of implementation.
I have tried various things for completion, etc over the years, and found Helm just too 'deep' of a topic to dig into... but vertico is the first time any of these things just 'clicked' and it's improved my experience of emacs 10-fold.
Somehow, I feel like, if I were to configure vertico etc to my liking, I might just end up recreating a ductaped version of helm.
You just unlocked a memory of when I found Helm intimidating just because some of its behavior surprised me on my initial tryouts. After reading the manual, it was actually much simpler than it had seemed.
IIRC helm doesn't provide complete-at-point so Corfu would be in a different category. Otherwise no, helm is really featureful and works pretty nice out-of-the-box, those packages are far more lean and probably easier to hack on.
My bad, so Corfu is in the category of Company mode.