Right now there are more coins available in the market which gives you more profit than bitcoin.
Bitcoin price is also not stable.
All these factors affect its popularity ??
What you think, still bitcoin is more popular ?
Bitcoin is still one of the best known crypto currency put there, let's be honest here. If you ask people on the street about Bitcoin they might have heard of it but if you ask them about litecoin or ethereum or any other coin most likely they won't even know what are you talking about. People see btc price to be as it is today and tend to think it is expensive for them to buy ad an investment so they move to more risky coins out there in hope to find the next goldmine.
If you pay attention if btc price goes down alts follow and reverse, bitcoin is still the king of them all and one in which most of the people have faith.
Bitcoin is still the base of all alts . To buy alts you need to buy bitcoin first ,thus it will never unpopular or irrelevant .
Yes other coins might make you more profits but i think of bitcoin as storing value that in the long run gonna make me profits on my assets too.
Bitcoin price might dump drastically if more alts became paired with other coins and there was no need to buy bitcoin first to buy alts.
Some exchanges offer different pairs like binance have eth and neo pair for example etc. But still most of exchanges have only btc pairs.