Yandex robots are driving around Moscow and SPb delivering food to people. Where are Nebius robots? "AI infrastructure" means just that they rent out GPUs they bought for themselves and did not find a use?

Comparing GDP means nothing. Having larger GDP doesn't mean the country is stronger, it is just a number.

Also in this case, you are comparing not the GDP (actually produced goods and services) but a "market cap" which is a virtual number calculated by price of one share multiplied by share count. Yandex shares, I assume, cannot be traded internationally so the number means nothing. Yandex has a public report where one can find out their revenue.