Look, if you think matchmaking is intentionally trying to place you into a division where your gonna average close to a 50% win rate... Your totally correct. That's how its built how mmr works, the entire point of ranked ladder. To be in a competitive environment with your peers.
However I don't understand why the hell you feel its gonna have additional mechanics that would actively interfere with it from doing that job mentioned above. Artificially trying to force 50% win rates gets in the way of placing players into their divisions where they naturally see that. If riot had a detection system that allowed them to hunt down highly toxic players then load them onto teams to slow down some ones climb, what value does this provide them? If they could do this what in the word stops them from using it to punish said highly toxic players and improve the environment for the healthy player base?
What's the gain for programing an incredibly complex algorithm that actively try's to sabotage players by looking for variables that are entirely dependent on a humans behavior, something the program has absolutely no control over. In theory I can see a mmr program wanting occasionally putting a player into a harder match then their division after a win streak because their raised MMR, if only just to prevent folks from getting lucky and climbing up the ladder because their divisions much lower then their MMR. Yet, we already a system for this in place and its clearly visible. Its called placement matches, they exist to break up the luck factor. What is the benefit to trying to double down on this?
You did what... 106 ranked solo que games this season. I want to know if you truly think that's a statically significant number of games to apply to the general populace and if its enough matches to make ya qualified to make the claim your getting hard stuck despite not even unlocking veterans badge in your division, which only exists to show players they have been at their division/mmr for a while.
Part of the conspiracy theories was meant for humor but I really don't think your giving this topic much critical though and analysis, you don't even mention what the hell the end game that artificially locking players via sabotaging their team would accomplish. Your claiming its true and it happens but not why or what its being done for, which reminded me of arguments I have had with a flat earth derp hence the jab/joke. Don't take it personally. I think your frustrated , I don't think your a crazy tinfoil hat nutjob.