The graph comes from usefultulips.org which uses Localbitcoins API
You may notice that the decline has started in 2019. That's when the platform began to impose identity verification if you remember.
There was a small rise last year, but I think it is because of the Covid situation. Anyway, it didn't last long and the number of transactions has really gone down in comparison to before. It's back to what it was in 2016 about.
I can't get recent data about paxful to compare but it declined in 2019 and the vast majority of its users are from Latin America.
This would mean that people are moving away from such platforms or switching to another one. Binance?
Anyway, I'm a bit surprised the company is taking such a large share of the market. I thought it would be at the bottom of the list...