what if Uber becomes an international holding company for ride sharing businesses?

Is that a better or worse future?

Uber lost some markets and won in others (e.g. LatAM, Australia). Also, it's not like Uber spent the money and got nothing for it - it's stake in DiDi is worth more than the amount of money Uber spent in China.

Many companies are facing winner takes all, so if your failures result in getting a significant stake in your competitions businesses, you’re doing pretty well IMO.

As much as I’d like that not to be the case for Uber.

But ubereats and other Uber subsidiaries that they sold were themselves over valued, You can see these acquiring a stake as diversification in highly competitive marketplace.

Without a doubt. And most of them won’t have the market to get the lofty valuations paid out (which didn’t even work in the best funded market - the US)

Yandex definitely isn't over-valued. It's undervalued, if anything.