Yandex cloud is not as big as AWS.

First of all AWS (even in us-*) most likely have non-US services\data. Yandex is mostly used by russian companies.

Plus, from my personal experience cloud is not as popular in Russia as in the west.

Big players like Sber, Ozon, T-Bank etc have their own datacenters and [may] use Yandex (or cloud.ru for example) for redundancy and\or non-critical services.

Small players use vps or something similar.

Big non-tech players (gas&oil for example) often rent redicated servers or space in a rack for their own hardware.