In cash games, the stacks are usually deeper, the blinds are always at the same level and you can top up the stack at any time. This means you should never "do something" as you might need to in a tournament. And it also means a more involved post-flop game. In connection with all this, cash games require a completely different strategy compared to tournaments.
Cash games are really harder than tournaments. And everything is explained quite simply.
First, tournaments attract more fish. As a rule, poker tournaments are shown on TV, so all their poker heroes are tournament players.
Tournaments allow you to quickly turn a small amount of money into a huge, with due luck, of course. And anyone can be lucky. We've seen it many times.