The single balance change I've advocated for in the longest time.

Nerf the trebuchet.

Reason why:

The trebuchet is a problem because it's almost always the best unit to get after you go imperial age, and ... every civ has it. That's the meme, go imp go trebs go win, I think for intermediate players trebs can close out exciting back and fourth games, very fast, which is fine, but every civ has a trebuchet. Which makes it kinda, meh for me. All of a sudden, you didn't win because armies clashed and your composition dominated, you won because you trebbed down his base and the enemy was forced to fight under your castle and you do this with every civ.

Potential solutions:

• Bombard cannons don't need chemistry to be made + AND either, have their damage nerfed to buildings OR, nerf bombard damage to all and give bonus damage to trebuchets. (you don't want bombard to resume the role of trebs)
• Nerf trebuchet damage lol, the siege unit is still gonna be insanely good, but give people more time to react.
  

edit. made text a bit more clear