That's also why for the highest security needs VPN+Tor is a recommendation. Although to be fair i personally believe if an actor is powerful enough to perform traffic analysis across the Tor network, they're probably powerful enough to correlate your computer activity with the VPN<->tor link.

Networks that resist metadata analysis are called mixnets and there's some interesting research about them. The downsides are you add latency (because each hop needs to randomize sleep) so bidirectional sessions like TCP is unthinkable. So nothing as usable as Tor Browser for checking your webmail or reading a blog.