SoftBank is not a telecom, it's a holding company like Berkshire.
They're an insurance company which monetizes through operating businesses rather than the traditional model of bancassurance.
http://www.berkshirehathawayhs.com/
They also own 100% of a heck of a lot of subsidiaries. They're not just minority owners in a bunch of companies like Coca-Cola.
https://en.wikipedia.org/wiki/List_of_assets_owned_by_Berksh...
If you're good at writing insurance it's essentially a great way of getting interest-free loans which they then spin into a huge pile of low-risk, cash-generating businesses (e.g. Duracell, Fruit of the Loom, See's Candies, to pick three Berkshire brands...).