I am not sure what Elon's vision of a "free speech" platform is, but if you allow absolutely all legal free speech, with limited/no moderation, it will turn into a cesspool.
This "Welcome to Hell, Elon" article sums up most of my points so I won't bother to repeat them all here.
https://www.theverge.com/2022/10/28/23428132/elon-musk-twitt...