I do agree that trying to trade with such a small amount wouldn't work, a 2-3% method would work if you have at least 10k dollars, because in that case it is 200-300 dollars, and you could make some money there, but even in that situation if you make as much money as doubling your money, that would be 300 dollars more to your 10k, nothing big right away, it has to be consistent and for a long term in order to say that you did well.
I believe if you have just 100 dollars, then the lowest you should go would be fifty bucks, because that means you will be able to make a lot more, something that actually means something. Once again, even with just hundred bucks, you are going to end up with consistent and long term results that would mean something, daily it won't be much.
It does not matter what kind of deposit you have, because if you do not adhere to the risk management strategy, you will definitely lose your deposit, no matter how big it is.
And if a trader with a small deposit follows your advice by opening an order for 50% of the deposit, then in case of 2 unsuccessful trades, zero of his deposit will remain.
This is the right way to think about the markets, if a person has such a small capital that a profit of a few percentage points do not really represents too much money for them, then the correct course of action is not to increase the amount used on each trade, since the risk of losing all our capital will increase as well.
The correct move would be to wait and save more money until our capital reaches a high enough amount and then we can trade the markets, it is true such a thing could take months or even years, but it is not as if the markets will disappear or anything like that, while all that time can be used to improve our strategy and our abilities as traders.