I searched other issues posted but they all seem to be related to unstable or otherwise having a different issue.
By default, with no drivers from Nvidia, Solus will "use" nouveau but that makes the whole system lockup at random. Symptoms may vary from cursor lockup to entire OS being unresponsive or very slow.
Basically, I managed to track down the root cause to onboard GTX 1050 inside XPS 15 (uses Intel + Nvidia). Blacklisting nouveau removes all the problems, and system boots and works as expected.
P.S. coincidentally I also need to install with
nomodeset
parameter otherwise the whole system freezes as well. I don't remember this being a problem on Solus 2 release when I first installed it.