No one knows what will happen in 120 years as we don't have a crystal ball. There are more and more people going to exchanges like Binance, Primexbt, kraken
Exchanges will appear and disappear but the number of bitcoins in circulation is limited and will keep going down.
I think that it's not early but it's also not too late. In time the expected profit will decrease but that doesn't mean you'll lose money. You will gain money just not 100x like you could 10 years ago. It's more like 5x now but that's still a great profit especially that you're gaining self sustainability, independence. No other investment gives you that. Even buying your first house can't compare.