I think deep buying is not a long-term investment strategy, it is a form of short-term market manipulation, although it can be profitable if executed correctly, but it is very important to distinguish between short-term strategic action and well-thought. -Out investment plan.
Actually long term investors can also utilise the dip buying strategy. But what is important is for them to back it up by continuous buying in the form of DCA either weekly or monthly while waiting for their maturity date. It will be more beneficial to the investor that he is making use of both DCA and dip strategies rather than just sticking to buying the dip alone
Deep buying can be profitable but it also has risks, you diversify your portfolio and you allocate the ability to lose it.
By portfolio diversification are you suggesting that the investor should invest in landed properties? Or shit coins? Well for me the best advice I will give is that if an investor gotten enough Bitcoin in his portfolio and is confident that the Bitcoin he has accumulated over the years will be enough for him and his future generations then he can diversify by storing up cash reserves. I won't encourage such an investor to go and invest in any shit coins in the name of diversification. It is better to have Bitcoin and enough cash reserves than investing in any thing that will cause you troubles and sleepless nights. After all Bitcoin has been the most performing asset over the last decade. I rather keep my investment in Bitcoin where I will have rest of mind than investing in several stuffs I don't really understand.