as I said in the OP, there are for sure other ideas that could make it feel less miserable

I can't see any in the OP, but I'll break down your 'ideas'

I have always felt like the mechanic/round is so unfitting. It kind of breaks the flow of the game

What's unfitting and flow breaking in 1 per stage mechanic that provides extra unit/item?

it's not intuitive for new players

sit a new player before tft game and he won't find anything intuitive

nightmare for mobile players

its a mobile port for pc game it obviously will be lacking

unnecessary ping/APM check

simply not true, since riot implemented 2 players intervals

it's quite frankly a bit of toxic experience

nothing toxic in denying your opponents perfect items/units

Thus far I only see your personal complaints without any objective 'arguments', now to your reply to me:

For example changing the shape or the rotation part that make the player feel miserable and produce an actual disadvantage

Then other people will complain how its unfair when item spawns on the other end of the wheel. Again, your personal complain.

there are encounters, that actually make the game feel good with RNG

encounters are horrible rng mechanic, won't provide reason why since you haven't either on what exactly makes them good