The code needed to handle as many users as Twitter has isn’t trivial.
But yeah most of the value is in the brand and the userbase. A big factor with social media is how it allows people to build friend networks that are bound to the platform. People can esily move to another platform, but convincing all of their friends to do the same is much more difficult. It’s insidious how it locks people in.
The fact that Musk is behaving like a complete asshat and people re staying there anyway just goes to prove how valuable that social media lock in is.
Of course AOL was valued similarly… just before the dot com bubble burst.