The reason for all the random changes.
NOTE: I am not agreeing with the reason. I'm not saying it is a valid reason. I'm just stating it.
It's pretty obvious. It's all for Worlds. Think about it.
: pick/ban in LCS, but poor SoloQ performance. Gets nerfed.
: pick/ban in LCS, below average in SoloQ. Gets nerfed.
: pick/ban in LCS, mediocre in SoloQ. Getting nerfs.
: becomes pick/ban in LCS if even close to viable in SoloQ
: pick/ban in LCS. Mediocre in SoloQ. Time for another rework.
pick/ban in LCS, strong in SoloQ as well. Ok he probably deserved those tbh
: pick/ban in LCS, good in SoloQ. Getting nerfs, but probably deserves them
: pick/ban in LCS. poor to mediocre in SoloQ. Gets nerfs.
Anyone noticing the trend? They're intentionally nerfing the pick/ban champions so it isnt the same 20 champions in every single game at Worlds.
The inverse is also true. Riot is also buffing champions (some have been buffed, others are currently buffed on PBE) that are currently fine in SoloQ, but seen as bad in the LCS.

and others that I can't think of off the top of my head
Notice the ones they're buffing champs that are ok, but can make #LC$BIGPLAYZ. Riven can make flashy plays and has a lot of outplay potential. Jinx can get one kill in a fight then run around going nuts. Jayce has flashy combos. Vayne has a lot of outplay potential and fancy footwork. Veigar has......ok maybe not so much Veig. Thresh has always been a #LC$BIGPLAYZ machine. What makes more hype than a big Lee Sin Insec kick?
With all of that being said, I cant wait for 2 patches from now where Riot can actually go back to balancing for real. Maybe something can finally be done about all these unwarranted buffs and nerfs. Maybe they can finally get to fixing some of these champs that were gutted and left to die too
I am kind of split though. One one hand it would be nice to see more than 20 champions at Worlds. On the other hand it is kind of BS that these changes have to affect millions of players' games for months. Although it's really not fair to people who enjoy to play but dont give a damn about competitive.
Overall I'll just be happy once we can get past the Worlds patch and can get back to normal.