This is because of CanvasGroups, their quality depends on graphics quality and are turned off completely when too much is rendered.
For performance, nothing was optimized during testing, the UI still has issues like empty report abuse tab on first open and lack of debounce for some transitions, it’s also the main source of lag on an empty baseplate.
Nevermind that fairly crisp x, look at how awful the redundant one on the leaderboard is:
(this was reported ages ago, but unsurprisingly it has not been fixed. How does something this bad even get released? The new chrome ui has been released for ages afaik)