You have to please the AI if you want it to like you. So what did you give to get those supposed better deals?
Deals are fairly useless as at most you get +10 and they degrade 1 point a turn so only of value for a short attempt
Open Borders +3 (stays while borders open)
Trade route +2 (stays with trade route)
Same religion +5 (stays with religion)
Joint war +5 (degrades 1 point per 10 turns)
Freed a city +5 (permanent)
Embassy +3 / Resident Embassy +5 (stays until war)
Denounced an enemy +8 (degrades 1 point per 10 turns while enemy exists
Same Government +x
Their Primary and secondary agendas +6-+12 <<< a big one, especially early
You need to get around +8-15 to get a good chance of declaring friendship or being offered it. First impressions is the only real negative and that looses 1 point every 10 turns.
Once a declared friend they always agree to being allies if you ask.
+9 for friends
+18 for allies
+8 for friend of a friend
+8 for friend of an ally
Great visibility and intelligence? Pointless in Civ 6
Complete BS... you ally with Norway at turn 90 and suddenly you see the whole board without exploring it. You also see any of your enemies troop movements that Norway can see. In my opinoin you are being inflammatory or ignorant. I just ask you consider it seriously because it does make for better wars.
I had to nerf myself and give more than I get in return to be considered as a partner
Perhaps you are warmongering the wrong way?
I am not going to type in about the 10th thread just how you deal with warmongering but it is even possible to be allies with everyone you have taken the capital of if you bothered to consider all the points of diplomacy. For a start liberating a city gives -32 warmonger. Declaring a surprise was not only gives 1.5 times warmonger for starting a war but for every city you take. If you want to take every city of a civ after the classical age you are just hobbling yourself in other ways and there is no decent reason to apart from feeling you own the world. If you want to play that way then thats fine ... just do not blame the game... blame yourself for not being able to play the game to its best effect.
I just started a game with Cyrus and Brazil next to me... I declared a surprise war on Brazil and Cyrus now loves me.... Once I get to allies he can start hating me for -6... it does not matter as I am +18 for allies.
I also could have declared a joint war with Cyrus against Brazil but it is 1 point less because it is considered a formal war so less warmonger but still done without warning.
If I had played like a wet cloth then Brazil would declare on me and they would have ended up being best buddies