So yes, if the 2017 date for your cousin shitcoinHoDL is early 2017 (which I would presume based on your 30x projection, which would be $42k/30 = $1,400 - and BTC prices would have been around $1,400 in early 2017), then 8.5x for DCA investing would be better than 3x for trading whether shitcoins or otherwise trading does not tend to be able to overall beat DCA, lump sum investing and buying on dips.  One aspect of presuming an ability to lump sum invest is to have the money available at the time that you first get in, but still many of us, remain concern about the reality that many normies do not necessarily have lump sums available at any given time and  also they can bolster their BTC allocation by using their future cashflows (while not necessarily wanting to take the risk of leveraging future cashflows in advance to lumpsum based on credit or something like that). 

For sure, many of us can also make mistakes along the way, so even if we do comparatively measure our actual returns with what would have been DCA returns, we might not want to kick ourselves too much if we underperform those returns or even to give our lil selfies too much credit merely because we may have been able to outperform the DCA returns.

One irony of my own particular situation is that I have happened to track the DCA returns pretty damned well, even though I had several pretty BIG losses due to dealing with exchanges, some transactions that I made with dishonest people who reneged on their end, a sim port attack and perhaps some other mistakes that I made.  I consider whatever experimenting that I did with shitcoins and also some of my attempts at spontaneous trading that resulted in emotion-based mistakes to have pretty damned minimal in the whole scheme of things.

I guess part of my point remains that if a guy figures out his own cashflow and various other personal financial and psychological circumstances, then he should be able to come pretty damned close to at least mirroring the performance of a DCA strategy - even if he might have been able to beat such strategy by investing early and just sitting on it, but I personally advocate a more active and ongoing strategy of continuing to buy BTC along the way rather than just lump sum investing which would also potentially include buying on dips (besides the core ongoing DCA strategy) and to stay involved to the extent that your time, skills and abilities permit.  And, sure of course, if you have either overallocated or reached fuck you status or something close to fuck you status, then there might not be as much of a need to continue with DCA, so at that point the strategy might just end up involving buying on dips and even eliminate the lump sum investing too.. except to the extent that some funds might merely be in reserve to buy on dips.

Regarding your cousin shitcoinHoDL's consideration that any of the bcash's are still a thing (whether talking about BCH or the quasi-more-delusional BSV) are any kind of meaningful thing shows that he may well be way too delusional to deal with, and maybe even to some extent, I don't even believe what I am saying here because I have several delusional twat relatives who hang onto the idea of Dogecoin going to either $.70 or even to $1 or more.. and some other dumb shit like Cardano, and I am not really going to completely give up on them, even if I might get annoyed as fuck when I am talking with them and I just need to take a break sometimes and just let matters play out for a couple more years or however long it might take to possibly revisit the matter - except to the extent that sometimes you may intend to NOT talk with these seemingly delusional twats (happen to be relatives) for a couple of years, but you know that you have pretty decent chances of running into them at various family gatherings.. and surely they might bring up the topic, even if you believe that it might be better to NOT talk about such topic.. but sometimes the topic might just end up coming up in spite your wishes, and you might not even be averse to discussing some of the matters again, even if you believe the relative is pretty far gone in their various presumptions and their analysis of factors that you conclude to be ONLY betting on upside without adequately accounting for downside - which yeah is a whole hell of a lot of gambling that some people seem unable to NOT do, even if they seem to know better, their actions kind of speak for themselves.