I think even after 20 years, Bitcoin might increase in value but it may also decrease, 1 BTC is not enough for retirement, since it is 20 years from now i think you can make more money than 1 BTC and make sure to have enough money for your needs so i think it is not enough and who knows if bitcoin is still the same after 20 years from now.
Yeah, you are right about that.
Even after 20 years that 1 bitcoin already $50k or even more, it's still not enough.
What? Only holding 1 bitcoin till 20 years later. No, Right now, everything is already expensive enough, then what would happen in 20 years later?
Everything will becomes more and more expensive than now. Maybe 1 btc would only last a couple months in the future.