> You lose a bit of ability to tell who is famous, but in exchange you get more significant bot and spam prevention as well a less advertiser dependent revenue model.
People who want to spam a cryptocurrency fraud will make a lot more than even a year's worth of Twitter Blue. Phone number verification is insufficient, you need to tie to a real world, unique identity to prevent spam.
And, Twitter has 450 million monthly active users (by some estimates - very hard to tell with how volatile the user base has been over the last few months). If you took an optimistic 1% conversion ratio for $100/yr subscriptions (typical freemium uptake metrics), that is $110 million dollars a quarter revenue.
Twitter used to get $1 bil in advertising revenue for quarter, which would still mean 90% of their revenue would come from advertising.
Unfortunately - estimates are that they have lost between 70 and 89% of their advertising revenue, the uptake for Twitter Blue is estimated to be well below 1%, and the leveraged buyout added a billion dollars of additional interest Twitter owes a year.
There's a general decline in advertising revenue, but some (such as myself) suspect the major brands looked at the volatility of Twitter and decided to target a disproportionate amount of their cuts there.