I disagree with you on this statement. No matter how expensive bitcoin is, new investors will continue to use DCA method to accumulate bitcoin. It all depends on the amount that you are using to DCA, that's what will determine if you will be able to accumulate 1btc in ten years time. If someone with a strong discretionary income invest in bitcoin for ten years and keep his bitcoin accumulation ongoing with persistent and consistent, he can achieve one bitcoin within ten years.
Plebs don't need to be over aggressive out of their discretionary, but to invest with the little amount of money that their discretionary income can withstand. If they are consistent and persistent in their DCA every week/months, they will be in a better place in ten years time eve n though, they cannot accumulate up to 1btc. The most important thing is to get started immediately when your discretionary income is available.
However, your accumulation years can go beyond ten years and it's not a must to stop accumulation after ten years, because what matters is your age and your bitcoin target in future.
Well like you said, it's a matter of consistency because that's the most important thing aside you already having the right tools which are source of income to back that consistency and when I say income it doesn't have to be something very bogus atleast you already knowing what you are aiming you can decide to work on that lane with what you have as your discretionary funds although I can say for certain and also can't dispute the fact that with the right tools made available 1btc.