I think Hoi4, due to being so barebones (compared to the older and more developed games, I mean) and (for me) having subject matter more approachable than duchies and consorts, is great for learning grand strategy/Paradox games. Since then, I've expanded to EU4, Stellaris, and Victoria 2 and prefer each of those to HoI4. It's also the game that got me into Paradox games (I tried HoI3, CK2, and EU4 first and never could get into them). I have over 600 hours in game and definitely enjoy it. I assume most people in this sub will say go for it.