When it comes to Bitcoin investment, just like the title of topic implies it's just best to "buy the dip and hodl", this is far better than thinking you could accumulate through trading which is luck base like you have already stated. Sometimes the availability of funds or finance is a major problem and also goes with impatient, many Bitcoin investor are mislead by the false stories about how trading is easy and actually try to venture into it by thinking they can get some Bitcoin added through this means to their investment but believe me it's not as easy as they make it seem in the ads and commercials and I Know this through the hard way(lost some coins).
If anyone actually want to be successful then keeping a strict mind about their investment would go a long and also knowing exactly when the market favours you so you can buy more (during dips) because you get more Bitcoin when you buy during dips or you can just go with weekly accumulating and most importantly never use funds that you know will affect you, thereby making you temper you Bitcoin investment.
The main option is also not wrong because some people may divide their fund allocation in half in investing. I mean they apply 50% for the long term and another 50% for daily trading or they buy when prices are low and sell when prices are high. So of course they can allocate the profits they get for long-term investment. And it's also not wrong because they take advantage of dips to buy and sell when prices are high and also they have long-term investments in the 50% of the funds they own.
Every strategy that is best for gaining profits is definitely of great interest to traders and they will apply the best to collect BTC for long-term investment. Apart from that, the moment of decline is always the best choice to buy more aggressively with what they have done before. So I also agree with you if you buy at a low price and hold it for the long term.
I agree with you that there are some people who do happen to maintain both a trading stash and an investing stash, and how much is allocated in each would be a personal decision... Personally, I believe that any more than 30% allocated to trading is going to put a person in the wrong mindset, and there might need to be some other guidelines in place for the trader, so that s/he does not continue to deplete the HODLing (investing) stash if the trades are happening to not go very well... no more than 10% in shitcoins and no more than 30% in trading, and perhaps if someone puts 10% into shitcoins, then s/he would ONLY be able to put up to 20% into trading because there is almost no way to justify being into shitcoins as anything other than a form of trading..
And, yeah in this thread, we are not talking about trading, so in that sense, any kind of acknowledgement of trading should probably be aimed at deemphasizing it and/or giving it way less than anything close to 50/50 as if it were something that any regular people should be considering, even if we know many of them are lured and propagandized into believing that there is some kind of benefits to including a trading strategy, when that surely is not the case for an overwhelming majority of people and probably an overwhelming majority of people should start out small if they do want to dabble in trading and maybe even limit that to less than 10% of their BTC stash, and if they engage in those kinds of practices, then they will be prioritizing the right thing, which is investing rather than trading and/or gambling, but on the other hand if they feel that they learn the trading skills, then maybe they could increase their allocation to no more than 30%.. not 50%.. 50% is just crazy and probably even professional traders should not be doing that... but hey, they can figure that out for themselves, even though here, we are neither addressing the concerns of professional traders and likely we should even be de-emphasizing trading so much as to only acknowledge its potential usefulness as being a very small portion of our BTC allocation in the event we were to want to attempt to dabble in such likely to be stressful, time intensive, and even likely to be losing our money practices.