There likely are some folks who can set up trading systems that are profitable, even that potentially out earns bitcoin as a long term investment, yet those folks are rare and they also should not be promoting trading as if it were a basic skill that is preferable to investing long term into bitcoin.
Many times we cannot even figure out if a trading versus a long term investment strategy is doing better until perhaps the passages of one or two cycles, and surely historically the guys who had mostly held bitcoin have tended outperform the traders, yet surely there are going to be exceptions in which traders have done better, yet those are rare, and there are not systematic ways to show trading techniques because they are way more complicated than the various buy and holding strategies that accumulation of BTC through DCA, buying dips, lump sum and holding.. and not getting involved in selling or trading or gambling.
Part of your problem is to seeming want to promote trading as if it were something that were obvious, when the fact of the matter, more than 90% and maybe even more than 95% of normies are not really capable of setting forth trading practices that are likely to outperform BTC accumulation strategies that mostly focus on buying and holding.
I like the fact that you have raised an important point about the complexities of trading vs long term Bitcoin investment. It is necessary to accept that while few people are excelling in trading, making profits, majority of traders are not successful at all. And this is due to the intensity of the risk taken overshadowed by the pursuit of quick gains.
Contrastingly, long term investment in Bitcoin has made the majority more successful in the practice and it has presented a more flexible and accessible approach. Even if it doesn't guarantee profits i has been able to reduce the emotional pressure, risk and complexities that people who do trading go through.
I will also concede that for traders, there are surely ways to make a lot of profits with volatility, so bitcoin fits the bill for volatility, and sure maybe in the end, as you suggested, there are ways that bitcoin is volatile in more predictable ways than some other assets that you might have otherwise been trying to trade and getting worse results in terms of figuring out both degree of volatility and price direction.. but that still does not mean that trading should be easily gone into by an overwhelming majority of normal people unless they are ready, willing and able to spend a lot of time learning and potentially a decent amount of time losing money while they are learning. which is less likely to be the case with solid investment strategies that last 4-10 years or longer..and yeah investing is not guaranteed either so folks still have to figure out a BTC position size and accumulating approach that is comfortable for their personal circumstances..
No doubt volatility helps traders make a profit. But don't forget that there was a time when Bitcoin volatility was low, a lot of traders were off the market. Yeah, nobody expected such thing to happen those periods but people who have been holding bitcoin for long do not need to care about volatility at all. Should a person continue to rely on volatility to make a profit or just buy and hodl and watch the market do the thing for you in the long run?
Day trading consumes time one could use for long term. Imagine buying at x day and the price dropped below the price you would want to sell as a trader. Then you have to wait for 2 to 4 days for the price to go back up above the price you bought for a few bucks of profit sometimes it takes a week or two for the price to retrace back up. But if you DCA through this periods every week there is more better profit at hand.