Yandex has some of the best programmers in the world. This was a surprise to me, but in the past 5 years, I've been spending few months a year in Belarus with various engineering team and have been learning a lot about this region.
Yandex has it's own school within the universities where they recruit the best minds early on and train them.
I've heard from programmers who now work at FB. That they could pass google's interview tests, but could not pass the Yandex test at all.
Add to that, Yandex Taxi is currently the second most popular on demand Taxi service in Russia. They might also be able to easily bypass many regulations we face here in US and get to a lot more driving data than google/uber/apple/lyft might have.
What does that mean? I think, the self driving car might finally give Yandex team something to do with all the talent they've been recruiting. So I would not dismiss their efforts at all. They could become a real force very quickly.