with an ideal franchising system, while smaller orgs may not be represented, the lesser-known but skilled players would definitely be picked up by franchise orgs.
they have a vested interest to be the best, after all.
I do agree that it results in a lack of straight-outta-nowhere underdog runs, but there will still be unknown players like Trent, making deep runs and somewhat of an underdog run in their own right!
Sentinels in your example would 100% remain in the franchise. However, if they perform worse they have not only the financial backing of the franchise created revenue but also the benefit of being a franchise org to pick up better players. I.e. the situation where they weren't able to acquire a coach due to finances would likely not happen in a franchise system.
It all depends on how it's set up. I will miss the T1-T2 matchups, though, and I hope Riot has put in serious thought into ensuring T2 doesn't die as it has in countless games so far. Ideally, there would be a wildcard spot in the league itself, or at least to international competition.
also, i don't think your opinion is unpopular at all. it's absolutely normal and a valid concern.