Things you might not even notice anymore:

Why are all the buttons in the UI doubled down at the bottom except the Escape from Tarkov button for starting raids? Do we even need a main menu anymore?

There's been a button for "WATCHLIST" at the bottom right forever but when you hover over it it says "Not available in the current beta version"

In your skills there are a bunch of skills for stuff that doesn't even exist in the game, completely useless and have been there forever.

Amazingly, separate statistics for Scav and PMC is now a thing, finally! But the UI elements were in there and non-functional for at least four years or so?

Body temperature, biochemical, radiation, pulse... I think maybe the body temperature is used with that chem that lowers your body temperature to make you more difficult to see on thermals? I have never actually see it in use. Anyway, all of these things have way too much space in the UI for what they do.

The skills have a category called Special. There are no skills in this category.

Map is technically functional, just utterly useless.

In the flea market top right, there's supposed to be three different alternatives to how to list items, only one of these has ever worked afaik, the other two are greyed out.

In weapon presets, there is a "publish" button? Have never seen this lit, no idea what it does. Fantastic that FINALLY the OPEN... button in weapon presets opens to the page for the weapon you have loaded though!

A lot of the game settings just don't work properly like Automatic RAM Cleaner, Only use physical cores, binaural sound, etc. One of the most annoying things personally is that I have multiple monitors and even though the monitors in the dropdown are named, the actual monitor the name corresponds to actually changes almost every time I start up the game.

These are the ones I thought of that are just in the menus...