I can’t answer your questions about Vue.js, could only speak about the Stencil part as I recently published my first small PWA using the Ionic pwa toolkit. I also have previously published a bigger app with Ionic Angular.
So I guess you are asking the questions in comparison to Ionic Angular right?
More useful I would say maybe no, building an app with Ionic v4 and Angular is still dope I mean. Smaller probably it will be. Regarding performance, except boot time should be same.
Big advantages of Stencil is that using Web Components you are less subject to code migration, I found that a big advantages, time and money wise.
But on the other side, advantages of Angular is that you have probably more libs, more tools, more tutorials, more people using it etc.
I found the learning curve of Stencil as every Ionic product, super fast
Also note, I build these projects alone, so I don’t have your background and don’t know your team. Maybe if your team is an experienced React team it will even go fast with Stencil as it use the Jsx syntax which I had to understand.
Finally thought, I like both, Stencil and Angular app. For my pet project I went with Stencil but in the same time I started a project for a client where I use the Angular version.
Like I said above, don’t know Vue, but looks really cool too.
So maybe you should just try out to build the same dummy app (like an app with a button which says hello) with all options and then you just pick the one you rather like and feel comfortable with
