If you rely on a central entity to validate transactions and whatnot, you technically don't really know what chain you are dealing with. You just think/hope that they are being honest, which they most of the times are, but please, you shouldn't take that for granted. It only takes one mistake or purposeful scam on their end that will cost you a lot of money.

Only when you run a full node you can be sure to seperate fake from real, which is why I find it so important that people run their own node despite the fact that I know most people will not do that.

In the end, Bitcoin isn't a magical save the world or country pill. If the monetary policies suck, the same corrupt political leaders are in charge, etc the standard they use doesn't really matter because they will screw up eventually anyway. I'm perfectly fine to have Bitcoin be an alternative money similar to Gold. People can adopt Bitcoin right now already. No need to wait for any government to introduce a Gold or Bitcoin standard. Screw them.