It's really easy to run into drama and negativity, regardless of who you follow
Twitter might be the right platform to start a business, or spread awareness about certain issues. That might be good, but the negatives easily outweigh the positives. This is coming from a former Youtuber.
First off, no matter who you follow (or how many people you follow, for that matter), you will run into drama or negativity. I guarantee it. When I was on twitter, I only followed around 170 people, yet I easily ran into a lot of Politics, random tweets bashing people (not even for good reason) and negativity. Don't even get me started on the trending page, there is a lot of drama on the trending page. There are some positive tweets, I will say that. But the negative tweets far outweigh the positive ones.
The second point is that you have to be very careful with what you say on the internet. This is especially true with Twitter, and is one of the main reasons I think no one under 18 should use Twitter. One major slip up and you're done for, no matter how many followers you have. I was talking about not meeting my goals with content creation, and I didn't get any sort of support. Not even discussion.
Which leads into the third point: No one cares on Twitter. Sure, you might get some replies, retweets, etc depending on what you post, but that's only 1% of people on average. I actually used twitter to vent about my personal life, don't do what I did.
In short, Twitter was (and is) a breeding ground for drama and negativity, I actually had to stop using Twitter. I don't recommend anyone under 18 use Twitter, and I only give Twitter a 2 star rating because of the very few positives it has.