[elif]

Carcassonne is what i use for that niche.

it is a complex game with a very simple ruleset (i.e. one-operation per turn, every turn is the same)

There is an ipad version which is better than the physical one (easier to learn since it only allows legal moves, automatically keeps score, automatically shuffles) Plus no clean-up.

If you don't have internet and are alone, you can play against an AI and still have a good time. If you have internet you can play 1v1 with ranked matchmaking opponents and continue to get better.

If you want to play in a group, you can play a local game passing around the ipad. I've played this way with a group of people who had never played the game before, everyone finished knowing not only the gameplay rules but with inferred nuances about strategy.