But we cannot go back to the past right now, and you're right that if someone wants to reach that level now, they will need to be more serious about their plan. Whether Investing 25% of your income will shows that you are serious, and if we can maintain this level of investment for some years, we may reach the level or even more but that will depend on how bitcoin operates.
For sure, if you are able to do a higher percentage, then you will get a higher stake in bitcoin sooner, so that if bitcoin ends up having a run, then you benefit from what you had already put in. Surely many normal people struggle to invest and/or save 10% of their income on a regular, consistent and ongoing basis, so I try not to presume too much about what normal people are ready, willing and/or able to do.
Surely there are some normal people who might be able to live comfortably off of $15k to $25k per year, and sometimes if those guys get raises in their income, and they go from an income that is $30k per year to $50k or even $80k per year, they may well be able to invest their extra income and continue to keep their expenses down... so then they may well put themselves into a place in which they can reach overaccumulation levels sooner than their peers.
Yes, the more the percentage you can invest, the more you can build your Bitcoin holdings, and as the price rises, you will get profit more because you invested more. However, as you said, not everyone can afford to save or invest 10% of their income every week; some people are struggling to cover their basic needs, so we cannot expect everyone to do the same.
Of course, some people earn little amounts of money, maybe like $15k to $25k per year, but they only live a simple lifestyle. However, if they later find a better job and get a salary increase, perhaps to $50k or more, while they still manage to reduce their expenses, they can use their extra money to invest more. For a long time, they can build wealth more easily than those who make more money but spend more than they can earn. I believe that discipline and how to manage money are more important than how much you earn.