There’s no bonus if you invest more, it’s all in percentages:
- 15 years at 7%/year
- 15 years at 9%/year
- 20 years at 7%/year
- 20 years at 9%/year
whether it’s €100 or €100,000, the percentages don’t change (just the wrappers/taxes if you exceed €150K in contributions to the PEA
).
It all depends on lifestyle: I know people who earn €5,000 net per month and can’t (aren’t able to) save, others who manage to put aside €300 with salaries we should (as a society) be ashamed of; and all possible variations in between.
For all we know, @Cynthia3 might:
- have quite a few expenses right now
- have a fairly frugal lifestyle that suits them
- be going through a period of reduced income
And we don’t know anything about their retirement either.
With €2,500/month instead of €500/month you can multiply all these amounts by 5, and with €25,000/month…
The important thing isn’t to invest (or earn, or even spend) the maximum but to find the right balance between:
- What we need to survive
- What we need to live
- What we need to enjoy ourselves
- What we need to please the people we care about
- What we believe others need more than we do
and everything this costs us in terms of resources (time, energy, compromises, etc.)
As I’ve written several times, there are 2 ways to have more money: earn more and spend less. Example (I’m simplifying): living in a small village, having a job you can bike to, shopping locally for less without owning a car, cooking all your meals except leisure outings implies much higher profitability than earning more and always buying prepared food/restaurants, etc., buying a car, insurance, fuel, maintenance, etc.
€64,000 in such a scenario will be sufficient to cover many expenses that someone who will have €300,000 but with a much more expensive lifestyle.
In short: everyone is unique in their own way and no two are alike 
The ACWI arrived in PEA quite recently (about 3 months I think), so it’s normal to find fewer mentions. I believe (but this is just my gut feeling) that after a year of the Trump administration, investors’ demand to diversify more has reached a point where it represents a market opportunity for fund managers.