System Specifications:
GTX 1650
i5-4590 3.20Ghz
16gb ram
Peripherals:
Logitech G402 Gaming Mouse
Logitech G213 Gaming Keyboard
From what I know, I believe this is caused by V-Sync being enabled or that there's no "Raw input" option. I do not experience this bad of input lag on other games. Other games are snappy and stuff, but when I play Minecraft: Windows 10 Edition, it takes a while for my mouse movements to register. To remove this, I have to manually go into Minecraft's settings file and disable V-Sync for this problem to go away but I have to live with a bunch of screen tearing.
Maybe just add a "Raw mouse input" option?
This issue has already been reported. Duplicate MCPE-98861.
You can add additional information or just vote for the solution to this problem in the specified report.