Yes, they mention they use libsql. Don't know why I should use them and not the product by the actual libsql authors.
We actually ran a benchmark to see how read latency degrades with distance from the database: https://bunny.net/blog/how-database-location-affects-far-awa...
turso also made it so your primary had to be in one location, but bunny will move it around based on latency on next boot.
Also, not sure about now, but historically Turso didn't have to best uptime.