Unlike Twitter, ActivityPub sites generally don't beat you over the head with follow recommendations. The goal is not to get you mentally addicted to spending hours a day on Social Media.
A Google search is probably the most common discovery mechanism. Once people start putting their Mastodon addresses on their web pages, it will start getting easier.
The fediverse is young. Don't expect a finished product when there has been so few man-hours and so little funidng put into it.
If you search for Twitter2, the fediverse is not it.
If either of those things exist for mastodon, I'm not seeing them, and half the people on here are saying, "this isn't twitter go away" while the other half is raving about how exciting it is to be the recipient of "#twittermigration"
Which is all very cute, but it does tend to give commenters whiplash, not knowing whether the responses they're going to get are going to be from one side or the other, or both!
Both replies absolutely coexist because of something simple: the fediverse is not Twitter. If you're looking for Twitter2, that's not it. If you're looking to build the fediverse by being a member and contributing to the discussion. You're going in a different universe, learn the rules :)
These all sound like features to me. If I want you to contact me, I will give you my e-mail address. Otherwise, leave me alone.
I can't communicate with anyone whose address I don't already know. There's no real "discoverability." Many people have multiple email addresses, and I don't know whether I'm communicating with the correct one, or even whether more exist that I don't know about. If an email address stops working, it just... stops working. Emails bounce back (if I'm lucky!) with no easy or standard way to say why, or what address to use instead. I could go on.
Email is great for point-to-point communication, modulo some of the issues listed above, but that's a very limited use case, not at all comparable to most social media. It's a poor replacement for Twitter, for example.