In reality, no one really knows if the golden days are over or not. Bitcoin, unlike stocks, has no limit to its growth. In the past, people could not imagine that the price of Bitcoin would cross the $100K mark, and this happened only 16 years after Bitcoin was created. Some successful people are saying that the price of Bitcoin will cross the $1M mark. It's up to everyone to believe it or not, but it's important to realize that there are risks independent of us that can have a negative impact on the price of Bitcoin. Therefore, invest only money that you will not regret losing.
Even if bitcoin reaches $1 million, it will only give a 10x return from its current price, and if we invest $10k, the return will only be $100k. This is also a huge profit, but years ago, it took bitcoin only 1 cycle to bring that profit. But as things stand, I don't think bitcoin will hit $1 million in the next 4 years.
Any asset as it grows big and matures, volatility and returns will gradually decrease, Bitcoin is no exception and it is experiencing that. We cannot expect bitcoin to increase 2000% or 3000% in this cycle like what it did in previous cycles. Volatility is getting smaller but in return it is getting safer.
I agree with you, we can never expect huge returns from Bitcoin investment like in the past, Bitcoin has been the most successful investment in the last 15-16 years, and Bitcoin is already very valuable, although Bitcoin will be more valuable in the future, we will not get as much return as before. The future of Bitcoin is bright but it is no longer a magical way to get rich quick, although nothing is certain, but we should not expect anything too extraordinary.
However, the price of Bitcoin will always be volatile, and Bitcoin will continue to be valuable with this volatility, and $10M in the future is also not impossible, so it is the right decision to continue investing in Bitcoin consistently with a long-term view.