Youtube is definitely addictive to a large population of people. If you can live without it, the only thing we can infer is that it's not addictive to you.
It's great that you're in the majority of people who aren't addicted to Youtube, but that doesn't mean everyone has the same experience that you do.
Not everyone, sure, but a majority. People can get addicted to anything; yet we don't just call any activity addictive -- only those where most people have a hard time controlling their behavior.
I don't think watching youtube qualifies (not just being on your phone, or watching tv).
But the real problem is that Youtube makes all this money but it still took a decade+ to start looking profitable. It's extremely hard to compete with them even if you somehow got over the network effects because it's hard to make money while also paying content creators. Google could do it because they could commoditize youtube's early unprofitability to their ads revenue.
Ideally, something like Netflix spawns and lets "amateur" content creators host as well, which solves many problems. But netflix doesn't seem interested and the few competitors doing that are still in the discovery phase.
Youtube is indeed a monopoly -- but it's not actually addictive. Since they started this war against adblockers I have found that I can perfectly live without it.
When I absolutely would like to watch an informative video (for example, about how to fix something on my bike, etc.), I first try to open the video in a private window (with ublock on); if that also doesn't work I try to use yt-dlp.
But I have completely stopped mindlessly watching videos that are not the result of a search.
There's nothing necessary about youtube.