Yes they are. Plastic bearing seats are not the mos durable thing, but mine lasted a good 3 years before it completely died from use.
I got it in 2016. It was my first unresponsive yoyo. I damaged it like i’ve done to no other yoyo.
https://www.instagram.com/p/BB74nqBqC6X/?utm_source=ig_web_copy_link
This is when it finally died on february of this year.
https://www.instagram.com/p/BuAglOJhwMx/?utm_source=ig_web_copy_link
I squeezed 3 years of skill learning out of that $16 piece of plastic, without it failing me once. That’s a tank in my book.