The thing is, when a trader starts trading and making money he gets overwhelmed with the easy money that he's initially got.
So he starts making bigger trades and end up losing money, then he gets impatient and starts throwing money on his trades.
In the process to recover, he loses more until the point of self realization hits and then he starts learning.
This is the learning process that most traders go through and it never stops. Some times we make money, some times we learn something.
How sure you are that it's easy money for the trader? Who knows? He might've held that trade for days, and being patient is hard especially when it comes to trading don't forget about that.

Based on what you're sharing, TBH that's me back then when I was starting to learn trading. Losing consecutive times, making bigger trades to recover those losses, being impatient that it came to a point where I feel that I want to recover it as quickly as possible, and in the end, I lost so much money and got liquidated at one point as well. During that time, I was looking at something and I haven't blinked for around 5-10 minutes I think.
At that time, I'm disappointed on myself because of what I did, but after 5-10 minutes, I took a bath, taught of my mistake, learned from it, and move on as well. Moving on is very hard to do especially if its hard-earned money, but if you want to be successful, you should learn how to do it. I stopped trading for weeks after getting liquidated BTW.
For me, there are way, way to many reasons why day traders lose, but let's not think that all of them are losing. There are still many out there that are making buckos off of day trading. Those are the ones who took years before they find a strategy that works for them and made consecutive profits on a monthly basis.
There's no one strategy that works every time. The markets changes and so does the outcome of our strategy every time the market changes.
Yes, not all traders might be losing money, some might be really good at what they are doing but there are many traders who do lose money.
It's the same story for me as well and I guess for many others too. Coming to the easy money part, some people do think trading is easy money initially when they make profits.
Just some clicks here and there and in some time you just made nice profits.