Slow rendering of entities

How is it resolved?

The resolution of this report is "Incomplete", meaning that a moderator decided that it doesn't contain enough information.

Based on what I've seen before, this resolution is likely related to the fact that bug reports that simply describe the presence of lag aren't accepted. To report a performance issue, the bug report has to describe a specific cause of lag, such as MC-252693 or MC-253502.

You have profiling report and description, what else is needed?

That's still just describing the fact that lag exists, not a specific cause of lag. "Entities cause lag" is very general and would be expected. A specific performance issue would pinpoint perhaps the pathfinding of an entity slowing the server down, or a specific entity item model being laggier than expected. A good bug report would also include reproduction steps.

For some context, here's part of the Moderator Message used for Invalid lag reports:

Simply stating that "My game is laggy" is not helpful for Mojang to diagnose your issue. If you can pinpoint a specific cause when lag happens for you, please open a new report for that specific issue. If you think this might be a hardware issue please contact Community Support as they might be able to help with your issue.

Keep in mind that Mojang is constantly optimizing the game and simply playing the game provides feedback to Mojang on which parts cause performance issues.

I don't know if you have an idea of what you are talking about, but I pointed that rendering entities is slow, there is also screenshot from the profiler showing which parts are lagging. If ever developer responsible of any optimizations will see that, he will know what to do.