Playing this game since beta which would be for 10 years now. There is so much missed potential that it would take an average military enthusiasts to tears. The developers don't value player's time at all. Events regularly require 4-5 hours on a two day basis for 2-3 weeks at the time to get rewards.
Worst off is that your actual purchases are not honoured long term. If you buy a vehicle that performs above average, you can expect it being adjusted into irrelevance some time later.
All the new ads showing modern vehicles don't tell you it takes dozens or hundreds of hours to reach those tiers of gameplay even after you pay for premium account and/or premium vehicles.
If you don't pay at all though, you can expect the grind to increase ten fold.