I can make a claim that the player count should speak for itself such as here;
https://www.statista.com/statistics/317099/number-lol-registered-users-worldwide/
Given that the IFS was rolled out mid-early 2015, judging by those numbers in the community it didn't cause a decline but instead League went right back to increasing (after a decline in 2014).
Does that mean that the increase was caused by a better community? No, not necessarily. But it certainly shows that Riot didn't start declining once they rolled out a new detection system.
A "better community" is impossible to judge accurately on it's own from the standpoint of the company much less an individual. The company could feasibly try to judge how much better the community is based on the number of people they punish for poor behavior now compared to before, but that value is tainted because the detection system will fluctuate whenever there's a change in it. And each individual is going to have their own experience with it. Some people hate the new community because they're peeved that they can't yell at someone for doing poor or because they were insulted, others enjoy the new silence because they never had an issue with just shutting up and playing.
So these opinions by streamers, interviews, podcasts, articles, and your anecdotes are pretty worthless at actually determining if the community is "better" than before.