There are at least two kinds of fools. Perhaps you are thinking of "ignorant fools" - people who could know better but don't. There are also people who basically just can't know better.
Chris Sacca, who went on to become a billionaire investor in companies like Twitter, tells a funny story [1] about how he made foolish decisions in the stock market and lost a ton of money. Over the course of his career he reverses his fortune and becomes rich. The message of the story is something like "Don't stop grinding or hustling" or something like that. I think he's a good example of the ignorant fool that I imagine you are thinking of.
There's another class of fool though that basically cannot know better. This could include a wide variety of people, mentally unwell, gambling addicts, desperate people, elderly, people with an IQ of 80, etc. These people flat out are not going to read books on investing, or whatever mitigation path you would recommend to the ignorant fool, and if they did, they might not understand them or be able to use what they learned effectively. This is something like an "inherent fool" that I was thinking of.
What proportion of people who are going to lose money on dogecoin are ignorant fools, for whom this will be a valuable lesson and a stepping stone on their way to better living, versus inherent fools for whom this will be a setback in an already challenging life?
I can't speak for all cryptocurrencies in general, and I can only share my opinion, but I'm pretty confident that coins like dogecoin are certainly zero sum games. The best argument I can make for this is that zero value is being produced from dogecoin. Money is being put in, eventually people will want to take money out, but with no value being produced all the money that comes out of the system will come at the expense of those who put money in. It's kind of the quintessential example of a zero sum game.
I'd compare it to the company Coke. I can buy a share of Coke like I can put money into dogecoin. Coke is going to produce cans of sugar water. People are going to buy that sugar water, putting their money into the system, and, crucially, never expecting to get it back. They put their money in so that they can consume the value that is the can of sugar water.
This addition of money to the system, and the consumption of value, are what makes owning Coke not a zero sum game. Money games into the system from participants who do not expect their money back. As a shareholder of Coke, some of that money will come to me. I can own my share of Coke and benefit from the increased value that comes from the value Coke produces and the money of people who consume that value.
Conversely, dogecoin doesn't produce any value. You can move dogecoins around, but nothing is getting made and nothing is getting consumed. Every participant who is putting money in expects money back. There is nobody analogous to the person buying and drinking the Coke. Worse, everyone is hoping for MORE than the money they put in to come back.
As a simple matter of math, there is no real way for this to work so that everyone, or even most people, can benefit. If someone makes money, then someone else loses it. In this way, dogecoin is not at all investment. You aren't putting money towards a company or a venture, you are just buying lottery tickets that may or may not be worth more later. It's a gambling game of musical chairs.
1 - https://www.youtube.com/watch?v=EYffNTLL7go