It doesn't effect any other coin bcoz Bitcoin is at the top from so many years and it can't be beaten
The difference in there values gives the answer...
we are talking about the effect of bitcoin to other coins , not the effect of other coins from bitcoin .
Anyway , id say bitcoin affect other coins in terms of demand . bitcoin is verry popular , thats why many people will prefer it other than trying out other coins .
Though other coins is still more better when it comes to other ourposes such as online transactions or for paying/sending money .
So overall , both btc and altcoins are still equal imo because both of them has thier own advantages and disadvantages