How many users can Mastodon take per instance in a single day?

A lot of people has been questioning why so many go to BlueSky, and I think convenience and familiar look to Twitter in the official web UI and mobile app, not having to choose an instance by having one pre-selected (although can be changed) and I was wondering if Mastodon ever had such approach, would any instance be able to handle a huge traffic and mass migration to the instance? Or perhaps shuffle by checking instances health, but then would that even be worse instead?

For those who don't know, BlueSky is open-source, can be partially self-hosted and has API usage available free of charge, also can be bridged with the Fediverse. Which comes a long way better than Twitter and easier to reach from the Fediverse. However, it does have some questionable connections. Not possible to have investments and control them? Weird, for anyone who has heard of LadyBird (web browser) which takes a whole different approach when it comes to investment and still managed to get heavily funded.

Most of the people in the Fediverse who joined having privacy as a firat concern is well-aware and hear often privacy comes at the price of convenience, I doubt people who waited this long to leave Twitter (not even YouTube calls it X, only has the logo X) was because of privacy concern. But even if Mastodon were more convenient to those people in such way, would it even somehow be able to receive 100-150+ thousands people per day?