I've been on Vocal and joined their membership program twice now and both times I canceled it in less than a month.
I got so bored over there. As you say, it feels empty. At least here on Medium there is an atmosphere, a community to get involved in and interact with. But with Vocal it feels cold and uninhibited.
The last time I was there they were on the cusp of introducing changes to allow for following of your favourite writers. Maybe if they make a few more adjustments to the social side of things I may give Vocal another go. But for now I'm gonna stick with Medium.
Thanks for sharing your experiences and good luck with your writing 😁.