If btc goes to 100k it will "only" have (more or less) doubled from its ATH.
Bitcoin's previous ATH was $20k and double that is $40k which was reached. Double that is $80k which will be reached too.
until up to now we were used to 10-fold, 20-fold + increases, so doubling the money has not been really special.
10x, 20x, rises are bigger than double (2x) rises

But this smaller reward ratio is paired with a much bigger risk ratio, since btc's swings in a correction period will also get bigger.
no it won't be bigger. If you have $1 worth of bitcoin when it goes from $10 to $20 you make the same amount of profit as when it goes from $1000 to $2000 or $40,000 to $80,000.
Same with drops. You would have lost the same amount of money when price fell from $1200 to $150 or from $20,000 to $3,200 (87% versus 84%) and when it falls from $500,000 to $100,000 (80%).
And the fear of FOMO will also become smaller, as people will at one point accept, that the train has left the station.
Irrational people will always act the same exact way, they will continue panic selling and panic buying no matter what the price is. The only thing that will change is the size of the market ergo their effects on the price.
Of course, should btc show convincing signs that it could reach 1 Million very quickly, then the whole picture changes.
Reaching $1 million will also be slow just like all the previous targets. There is no reason to show any signs or even reaching it quickly. It is all a matter of adoption and adoption happen slowly.