As noted by security researcher Will Dormann, some posts on X purport to lead to a legitimate website, but actually redirect somewhere else. In Dormann’s example, an advertisement posted by a verified X user claims to lead to forbes.com. When Dormann clicks the link, however, it takes him to a different link to open a Telegram channel that is, “helping individuals earn maximum profit in the crypto market,” he said. In short, the “Forbes” link leads to crypto spam
You can manually set things to be private, but I don’t know if there’s any way to set everything as private by default.
It has the problem with all Facebook alternatives where they feel like Twitter without post limits.