Currently, there’s auto-generated base decor created around buildings, including decorative bushes, pots, fences, gardens, etc. One idea for cosmetic packs that players could purchase to support development of the game could be cosmetic packs for base decor that you would be able to use in your multiplayer games.
These wouldn’t change the appearance of buildings, or units, so readability would be much less of an obstacle, and you could utilize assets from previous events like enchanted grove to create some of these.
Themes could include general ideas like “gardens”, “festival”, “enchanted grove”, “naval”, “bandits”, etc or could be faction specific, like “chinese new year” or “oktoberfest”.