The only trading strategy which have potential to work in an unpredictable market is long term trading, which involved the trader holding for a long time period, up to few years... That is why patience is needed. On the other hand, for daily traders there aren't any assurances they are going to make guaranteed profit from this activity in a daily basis, therefore to rely a living from trading is too risky due to market's conditions.
And doesn't matter how professional and skilled the individual is on trading matters, he still can't forecast the next movement of crypto market accurately. These people making a decent living from trading you mentioned must have another sources of income to ensure their finances continue doing well in case trading fail along the way.
When the purpose is to hodl Bitcoin for a long term then it is no longer trading but investment. Trading is always for a short time purpose then investment is when an investor is accumulating Bitcoin either with the DCA strategy and hodl for long within a period of 4-10 years and above.
And also stop referring Bitcoin to crypto so be careful when you use the word Crypto so you won't get people confused here so if it is shitcoins you are talking be specific and say shitcoins if it is also Bitcoin then it is Bitcoin and stop using crypto as it generalises the entire cryptocurrency market.
This is because when people hear crypto they already believe is a scam investment expecially for new investors or newbies been specific will put a clear understanding in the mind of those investors.
I don't know why people even talk about trading here especially that the discussion flow is all about holding. But if they really want to test out the market by trading then do it since they are the one could able to choose what they want to do with their funds. But I highly discourage people to participate on this especially if they have lack of knowledge since we all know market is so risky and there's so many things need to think about and this activity is not newbie friendly since there's huge chance for them to lose their money on this.
Maybe they should come up with less risky investment and for sure they would love to do DCA especially if they execute it already since it introduce them the lower risk investment since they could able to acquire bitcoins at any price they want to purchase and they could not care to much about the volatility since by this method they are using it can make them ignore those things and the one will be in their mind is they are doing that because they have target years set on their journey done with hodling bitcoin.