10 or 20 years from now, when bitcoin's market cap equals or surpasses the gold's market cap, we will look back and think how lucky the people who bought bitcoin when it was under $1,000,000.
If many people who are complaining about Bitcoin's price being high can think of a time when Bitcoin's price may go even higher, as you have said, they will stop thinking of the price as high and just start buying now. They will then see Bitcoin's current price as not that expensive.
What most people complain about is the price today, but the focus should be on the future price of Bitcoin. With this mindset, they may feel encouraged to accumulate Bitcoin now and view its current price as cheap. In fact, it’s even possible that the price could reach significant milestones, such as $1,000,000, before the 10 to 20 years often mentioned.
One thing is certain: those who buy now and hold until Bitcoin's price reaches such heights will see themselves as the lucky ones. On the other hand, those who see the opportunity now and choose not to buy will likely experience great regret in the future.