@Riot Why are MMR, key frag drop rate, and premades hidden?

All of these items are highly useful pieces of information, yet we don't have access to them. If there's a good reason why, I could understand, but I haven't heard of any reasons.

Being able to see my MMR would help me understand what kind of LP gains/losses I'm looking at also well as demotion risks. Because I occassionally go and play other games and stop playing ranked for a period of time, I'm subject to MMR decay about twice a year. Then when I come back, I have absolutely no idea what my MMR is.

We've been told that key fragment drop rate resets every month and starts off high and then lowers each time you get a key fragment. But we've never been told what drop rate it starts at and how much it lowers per key fragment acquired. I can get 4 or 5 chests a month, but I have absolutely no idea how many wins on average it takes to get an equal amount of keys. I really wish I could figure out how hard I would have to try in order to keep up or whether I should just give up hope on ever catching up to unlocking all my chests.

And knowing who is in a premade is one of the most important pieces of information you could have in a ranked game. There is a huge difference between playing top against a premade top and jungler combo compared to playing against a solo top player.