Limiting both is a good policy, but understanding the different games is also an important aspect here. When my kids were in elementary school I encouraged them to play Minecraft and I played with them. I didn't prevent them from playing Clash of Clans because so many of their friends were playing, but I made sure they understood how incentives were structured and how the game was designed around that.

That was ten years ago, and I still don't know if I struck the right balance. Parenting is hard. If you have young kids today it's a good idea to understand what games are popular and what their business models are.