Interesting article. It's been a few years since I've had a play with this kind of stuff; what's the best option available for someone to host custom styled vector maps and display them in a performant way? preferably on an open source stack. I haven't used MapBox before as I was worried about costs and being locked in. I'm interested in experimenting with map interaction/UX.

There's some forks of pre-closed source Mapbox

https://maplibre.org/

https://github.com/maplibre/maplibre-gl-js

I've used it on a smaller project, it worked well for me.