There are diminishing returns sure, but the more money that piles in as adoption increases means demand will still be there. Obviously the days of the price going from $1,000 to $20,000 for example 2013 top to 2017 top are gone. But significant profits can still be made. Double 2021 top of $69,000 would be $138,000 this year which is possible in my opinion. Then we will see what happens going forward. Bitcoin is still a great investment but newbies won’t get rich off it any more. They can still build part of a retirement plan with it though. I see $1,000,000 per coin before 2050.