I think the quantity of these minor annoyances is one of my biggest grievances with Civ 6. It feels so... unrefined sometimes. Here are just some pet peeves / annoyances that I can think of on the spot:
- For some reason, there isn't always a notification that another civ built a wonder. The wonder notifications remain on the sidebar for the entire game until you close them, and when you look through these notifications you'll find that many wonders don't have a notification and never did when they were built, so you have to use the map search to find the wonder and figure out where it was built and by who.
- You can break a promise not to convert cities even if it's religious combat that converts the city, and note that you don't even need to be the instigator of this religious combat for it to count as a broken promise. An AI's apostle can die in an attack they initiate on your own religious units and they'll still consider it a broken promise if that death causes their city to convert, even though you had no control over it.
- Even when embarking and travelling across water is much faster than travelling on land to a destination, units will still disembark and travel on land.
- When open borders end, your units are kicked out of enemy territory.
- There is no prompt to refresh alliances or friendships when they end.
- No way to stop or penalize allies that attack and conquer your suzerained city states. This is a big one that I know many have mentioned already in this thread.
- When you're at war with a neighbour and have to fight in neutral or enemy territory near the borders of other civs, those other civs will tell you to move your units away, and if you continue to fight in the territory of the civ next to them, they'll consider it a broken promise. This might make sense in terms of immersion but it's just annoying in terms of gameplay IMO.
- Almost every time religious units move in enemy territory, the blue hex outlines that appear that show where the unit can move are not visible, so it looks like the unit has run out of moves or can't move to certain tiles in that turn unless you try to make it move there. This will then happen repeatedly if you move one tile at a time so as to not run out of moves too early.
- It's difficult to tell for sure how much movement it will cost for any land unit to move to a given tile, so when you have units that can perform an action (build tile improvement, spread religion, etc.) it's often very tough to figure out if the unit can move to a location and still have at least some movement remaining so that it can perform an action. A solution for this could be to have a little number appear when you're selecting a tile to move to showing how many movement points will be expended if you move the unit to that tile, and/or how many movement points will remain.
- Sometimes, when dragging the map, the camera locks onto your cursor so when you move your cursor anywhere the map darts all over the place. I can't tell if this is meant to be a way to move the map or if it's a bug, but I also don't know what exactly causes it to happen.
- AI is often predictable in the ways they vote on certain resolutions. For example, they often seem to vote to ban a luxury the player owns, frequently vote to prevent Great Prophets or Great Admirals (why?) from being earned, and always commit just 1 vote to themselves to try to win the culture bomb resolution (I don't mind that, because it means I can always get the culture bombs, but it shouldn't be like that).
- No way to sort trade routes by highest yield.
- No way to sort cities in the city report screen by highest yield.
