You provided a bit of information about money but you didn't provide any insight into what a moneyless society might look like and you didn't provide any information to convince someone that this is a feasible concept

That's simply because I'm not particularly well-versed into the advantages or disadvantages of moneyless societies, and I'm not particularly for or against them, if anything I'm im favour of the existence of a centralized currency as we have now. My point was only that discussion is l best done when nuanced and interested, and not "but avocado". My point was also that Marxist terms are to be discussed and revised at all times, and maybe you're right and moneyless societies aren't the best alternative given our modern knowledge of money.

Regarding the second half of your paragraph, my problems with IOUs are a bit different. The problem with non-centralized, promise-based forms of money, is that they're very prone to being violated, and that barter is a very inefficient form of exchange of goods and services. I'm not well-versed in the concept of a moneyless economy, but I'm a bit more well-versed in the nature of money. For example, money's worth doesn't come from "everyone agreeing that it's worth something for some reason". It comes from taxation. A central authority, in this case the state, imposes compulsory taxes using the monopoly of violence, in a given currency. The fact that people will have to pay their taxes in that particular currency, means that they need to obtain that currency in the first place to pay said taxes. This makes people more likely to engage in economic activity with that currency, since it's suddenly very useful for everyone in order to pay their compulsory taxes. Taxes are also very useful as a redistribution mechanism. All in all, a central currency whose monetary policy is decided collectively by the workers in a democratic fashion, can be argued to be a useful thing for a democratic communist society. I'm sure there are arguments against this but I'm not very well versed in the critique as I said.

Conclusion: question everything, but let's do it in a serious way to improve our knowledge and to possibly envision better societies.

Are you familiar with the bartering system? Rather than money, you would judge the value of the object by how much you needed it. If you really wanted the avocados, you would ask the person who had avocados what they would trade. If you didn't have what they wanted, you can bargain or try someone else who has avocados who wants what you currently have.

Basically, a money less society goes back to a very simplified society. You won't be able to get everything you want and will have to, sometimes, settle for what you currently have. It also gives you the ability to trade your skills.

So, you go back to the avocado trader and tell them that you'll build an avocado shed for them in exchange for a crate of avocados. You both negotiate, exchange and then move on.

It's more work because you have seized the means of production by making things yourself in order to trade, rather than off shoring to someone else who is likely not getting paid at all. This is why the wealthy absolutely don't want this system because it's more work for them, while in the lower class it'll give more control back. When balancing, there will always be people who lose and people who gain.