Investment requires determination and dedication because to have efficient investment you must sacrifice many things and deprive yourself from some luxury lifestyles which many people cannot persever. The major problem some people are having in Bitcoin investment is not just capital but the adequate knowledge of the process and how the system work.
Bitcoin is a digital currency which most of the investors does not have control over the system, so most people that doesn't have the adequate knowledge of it and the orientation are still afraid to make a huge investment in Bitcoin believing it to be a Ponzi scheme that has the tendency of crashing any day thereby making people to loose their hard earn money.
depriving oneself from luxury lifestyles inorder to Stash more Bitcoin is a smart move, because if you start stashing more bitcoin now and HODL in a long run , would give you a life far more better than living a luxury lifestyles now. So bitcoin investment is all about work hard now and enjoy the fruits of your labour later.
While those that still having that thought of bitcoin being a Ponzi scheme would keep on missing such opportunities, because they don't wanna learn , that's how alot of individuals back then may have also have same mindset thinking bitcoin is a Ponzi scheme and would crash soon when it value was still around $1k , but through those years bitcoin kept proving them wrong and now Bitcoin just recently hit a new ATH (which Is around $73k ) not quite long. You can see the tremendous growth and we believe bitcoin would still keep on proving them wrong , when it keep going up.
Ponzi schemes usually don't last too long. So that can be a benchmark to offer to people who still think Bitcoin is an investment that uses a Ponzi scheme.
as you said we can provide real evidence of the price of bitcoin when it was still $1K until now. or if necessary, you can use data from the first halving to the last halving next month. how does the price of bitcoin increase from each halving or from year to year. of course they will see clearly that this is real and not a ponzi scheme as they say.