Yobit is a scam exchange, avoid it. Actually you can search yobit accusation on this forum, you will get many accusations shown on the google. Although there's currently no accusation against Yobit, maybe no one ever use this exchange again since there's no interesting promotion to attract new people. Yobit campaign was success since they're massively promoting in this forum by spamming the whole forum.
It is not scam, it has its own "strange" vision of how to do business. If it was a complete scam, it would not run airdrops or better say competitions (even though the amount obtained there is laughable), and people wont trade there at all. So far it operates, a lot of people in Russia make YoBit as their prime or only way to turn crypto into fiat.
But I would not recommend YoBit as an exchange to trade huge amounts. In case something goes wrong, users has an issue or any other unexpected things happens - you wont get any help from support. User can write as many support tickets as they want, but it is quicker to get a jackpot in lottery, then get an answer from YoBit support.