Mastodon is a decentralized service based on open source. This makes it virtually impossible for the platform (or network) to be controlled by single interest groups. Many people work together to make the platform available. This is good for diversity, and anyone who feels harassed by individual accounts or entire servers can simply block them.
However, since there is not just one company behind the service and servers, users have to put more effort into finding the right Mastodon server. Also, keep in mind that the operators of the servers can stop this service at any time. This could mean that all your contributions would be lost. So, you should choose a server where this is unlikely to happen.
Mastodon is not considered very easy to get started with, because you first have to get to grips with the concept of Fediverse and learn about the individual instances. However, once you have registered, the handling is very intuitive.
So far, Mastodon is still relatively unknown, but the registration rate has increased significantly. (As of November 2022). Above all, well-known personalities or brands that have a great appeal are missing on Mastodon so far. However, this may change in the future.