In 1.16, if you join a featured server such a cubecraft, mineplex, or the hive, rapidly opening and closing your inventory quickly a few times will crash the game. (Not to mention I cant even open my inventory on lifeboat).

Additionally, if you join another multiplayer world (particularly a laggy host), you will notice that there is server-side lag in bringing up the menu. Inventory opening should be a client-side operation, but now in 1.16 for whatever reason it acts like it needs a server-side check. This can best be tested by turning your screen animations off and opening your inventory, because the period in which your inventory UI does not show and when it shows is more concise. The input lag is very noticeable and detrimental to gameplay on other peoples worlds and EU hosts as an NA player. 

https://www.youtube.com/watch?v=l2-BqjjMc-g&feature=youtu.be

Here is an example from the hive network. There is input lag when opening my inventory and all of a sudden it crashes. On cubecraft, it is instant. The red screen at the end is my game crashing.