I'm fairly sure they've given up on massive battles but they can barely keep a 60 player server without either the game lagging or the server lagging. Less unnecessarily detailed map and player models will help one problem at least.
Honestly, I think EC's models are too high-quality, and it would have been beneficial to make them less pretty and easier for computers to render, to improve performance. However, I also do not really enjoy hyperrealistic graphics, and prefer a more stylized art style, but that's my personal preference and I have no objection to the choice bE made for EC's art style. EC's graphics are developed far enough that reducing the model quality at this point, to improve performance, is probably the wrong choice, and I think the massive open world EC is going for in the long run is far enough in the future that EC's graphics will be dated enough that it will not be a huge issue by then.
Polygon count does not equate to quality. In fact, with what they achieve for all those polygons I'd say it's a mark of LOW quality, not high.
How does this concept require explanation? If you want to catch a mouse, you use a mouse trap, not a Rube Goldberg machine mouse trap. If you want to make a fast paced action game, you don't need Pixar movie quality models. There's corners you can cut, or more appropriately for 3d modeling: corners you can keep, to save a lot of resources.
Sacrificing quality for performance does not make the graphics higher-quality just because the game runs more smoothly.
Quality is measured by how well the thing you have does the thing you want it to do. If the performance of the game suffers as a result of it's artistic merits, that's not a high-quality product. A golden sword may look beautiful by your side, but it dulls and breaks quickly when used for a swords intended purpose.
