If DeFi wasn't that seriuos, why would banks and entire governments be fighting it?

To anyone doubting DeFi and it's capabilities, you should consider that governments wouldn't waste time, energy and resources trying to fight it. But as we recently saw with China banning crypto mining and the SEC fighting DeFi, it's a too concern for most governments right now.

Governments see that people will inevitably make the move to DeFi. Why would anyone settle with a maximum of 2% APY at a bank after they find out about platforms like UniSwap that offer MUCH higher APYS or platforms like Ramp that offer zero interest on lending. Banks simply can't compete with that and when banks lose power, this translates to the government losing power. DeFi will take over eventually, just watch.