Is the best way to get better, to simply play more games?

Not all of them are, but if you don't put the time in you're not gonna get better. If someone says "this is an easy way to get better", don't listen. You gotta work hard to be good.

Nah, been playing since late S3 or so, still stuck in Silver(or Gold when I feel up to it).

Watch replays. See your mistakes. learn from them.

step one- play a few rounds with high level friends.

step 2- start playing more

step 3- watch youtubers karp crew- I know they aren`t the best, but they might be the only ones who keep it interesting enough for you to finish the video.

step 4-dont be a toxic jerk

step 5- freelo

Your mentality is a big part of improving. If you actually actively try to improve, you will. If you just grind out games and learn nothing from them, you'll stay at the same place for years.

Ive played since season 2, with about a thousand game each season. Still not high elo by any stretch of the imagination. I tend to be unlucky with teams, I also have ADD which makes it harder to learn and play the game with full attention. Also does not help that I play with a consumer laptop from 2010 with Comcast internet.

I'm sure though if someone else played as much as me they would be in diamond. I take in a lot of education content too but most of it hasn't helped. I'd say challenger replays have helped the most, with youtube videos being near pointless and r/summonerschool being completely useless. They all say the same thing, basically "if you want to improve you have to focus on your mistakes". Which holds no relevance on the actual game. It's more of a general life philosophy which is not realistically applicable.

The truth is to get better at something you need to spend ample amounts of time learning it. This is why we go to class every day for hours instead of taking 10 minute crash courses. When I was trying to improve at chess I would watch hour-long lectures on the breakdown of beginner and professional games. The same applies with getting better at League. You can't improve with short youtube videos like "10 tips to get higher elo". They simply won't do you any good. If you really want to improve you need to watch hours upon hours of challenger gameplay footage to see any real progress. It's not necessary but it's the most efficient way to improve. Like going to the gym or losing weight, it takes hours upon hours to see any improvement.

Sorry for the rant, I know it's not what you asked for but hopefully it helps.

EDIT: Many people say to watch your own replays, but there is so much trash going on in low elo games that it is just better to watch someone else in challenger. There is so much less mistakes that makes it easier to analyze, copy and learn from rather than watching a bunch of monkeys play LoL.