Experience always starts at losing that's why it's better for me to see newbies having a tough run while they progress.
I agree with your points of view. Mistakes improve a man's knowledge and experience. It is important to learn from your mistake and if you make the same mistake simultaneously then you are not concentrating. Every time a trader makes a mistake a short note about it should be taken so that he can improve his strategy by finding out the reason behind that bad trade.
In my opinion, the mistake of most investing and trading anywhere is because of fomo. Dare to go all in with all asset transfers to one of the assets that he "considers" as a get rich quick vehicle. Even though there are many steps that must be taken, one of which is investing or trading responsibly. I mean you have to really understand what you want to invest in.
But people are lazy to do that, then choose to trade and invest. What's worse is not using diversification, not understanding the risk profile, not understanding what assets to invest in, and never turning mistakes into experience.