From memory...
Twitter was 16 years old, but had just two profitable years.
Elon paid a total of $44 billion, including TWTR stock that he already owned, plus TWTR debts that he inherited.
He could have started a direct competitor for $1 billion, and probably have been profitable by Year Three.
The amount he paid for Twitter was completely insane.
Yes. He could have started X.com. But no one would go there.
There are still many conservatives on facebook, even after Zuckerbucks helped oust Trump. People won’t leave because they’d lose all their connections. The people who did leave ended up in a diaspora with some going to Parler, some to GAB, some to WeMe and some to Truth once available and some to other smaller sites.
No alternative to facebook has become big. That’s why Musk bought twitter. He could have started a similar site but it never would have gotten big like twitter. He bought an existing community more than he bought a website tech.