Why did Tele2 make a cheap completely unlimited tariff?

Question

Telecom operators

Nevertheless, it became interesting, from a business point of view, what is the benefit of tele2 in their new tariff, since 2015 there was a tariff for 250 rubles per month, called all over Russia unlimitedly to all operators and used 15 GB per month of mobile traffic, now they generally did full unlimited internet without 4G speed limit - for 300 rubles per month. So I'm wondering, is it profitable for them or will this tariff soon cost around 1000? I bought a 4G modem, inserted it into the router, I have been downloading torrents for a month now and have used more than 700 GB of traffic, the speed has never been cut, the speed test always showed 40-60 Mbps, it works faster than Yota - but worse than the beeline, sometimes breaks.