I think trading capital ultimately depends on the trader and how much they are willing to lose per trade. There are traders who can take a $10 or $20 trading accounts to the highs of $5000 - $10000. Anybody can do it if they know what they're doing. It's very much possible these days since you can trade crypto futures and even use leverages. Your patry $20 capital would be $200 when on a 10x leverage account.
Anyway, I'm not here to talk about leverage trading. The point I'm trying to drive home is that any trading capital should be fine as far as the trader is comfortable with it and knows what they're doing. But one thing is clear those, the more the capital, the more you're likely to profit per trade if it goes well - for instance, gaining 500% on an $10 account doesn't seem to be worth it considering you only get $40 as profit. Compare that with a $500 - $5000 trading account.
I am very much agreed to your explanation Sir, there is really no problem with the capital whether it is small or big.
The really thing important is that the individual traders knows what they are doing inside the trading platform were in the end
they could get a nice profit of course. In fact, in my experienced I started with a small capital amounting 20$ then within a week I can make it turn into 50$ - 100$ or more something like that even up to the present.