If you can save up to ten years in this way, there is a possibility of increasing the profit several times.
Bitcoin doesn't pay profits, the value of your investment is what keeps increasing, the more you expand your portfolio, the more the the value of your investment increases when the compounding effect of Bitcoin price appreciation acts on it positively and the value of your investment increases by a better margin 1.5x, 2x or more.
The value of your investment compound upon itself as Bitcoin price goes higher and the new higher value still keeps compounding on itself as you hold longer and Bitcoin keeps doing better, so what you're increasing by constantly investing and holding for the said 10 years is the value of your investment and not the profits
I don't really understand your argument here, because the both words are similar in meaning in this context. I don't think an investor is wrong if after holding his Bitcoin for let's say the 10 years you are talking about, look at his portfolio and say wow, after investing certain amount during the period that this is the profit in my investment so far. If by that 10 years he spent like $10k in accumulation and his Bitcoin value rise to $25k is he subtracts the $10k invested won't the balance be called profit? This your argument is baseless truth be told.