I personally don't like the fact that they just keep expanding it man
I would prefer if they reused existing mechanics in interesting ways instead of introducing new rules with every expansion. The game is very non-beginner friendly now due to the abundance of rules introduced with each expansion.
I recommend not playing full random with everything if you're teaching the game!
Definitely second this. As someone who has personally introduced Dominion to 10-15+ people, nothing kills interest faster than making new players learn Exile, Debt, Duration, Coffers, etc. while they’re still grappling with why you need a Village to play two Smithies in a turn. Start with Base and sprinkle in new sets/mechanics one at a time.