Wonders are ruining team games

Exactly, I play custom games and never have to worry about wonder victory. Because most people disable wonder victory

The resources required to build a wonder should increase based on the number of players. I propose:
2-player teams 3,500 of each resource.
3-player teams 4,500 of each resource.
4-player teams 6,000 of each resource.
Notice that the increase in necessary resources to build the wonder is not linear considering that the more players there are in a game, the more you can feed a player to build it.

How about building a wonder gives your opponents +0.5 damage per unit per minute that counts down?

In aoe2 : Wonder is too expensive to be used.
In aoe3: Wonder does not end the game.
In aoe4: …

Island maps I can see your point. It takes forever to get your army together to try travel across the water, make land, and then fight your way to a corner where the wonder is placed. Way too short in amount of time.

I think the issue stems with other team members not taking the built wonder seriously. Once your opponents wonder goes up, there should be coordination immediately with team to work your way to one area with all your army. I’ve seen team members do silly stuff like attacking an opponent that is no threat while 1 person is only focusing on the wonder.