Right now most people prefer to use BTC because it doesn't have the memory backlog like it did back in Q4 2017. Basically if you are patient you can send transaction using a 1satoshi/byte and it would get confirmed within a day or so.
But still people do not like to wait for this long just to get their btc into their own wallet even though it will be added to their wallet in the end. Because of the volatility people want to get it ASAP
The issue with alts like Doge, LTC and ETH is that we are in an alts capitulation mode and they are getting heavily sold against BTC. Everybody is selling their alts and buying BTC. So people rather not hold any alts.
But this is the big 3 altcoin that have the best possibility to gain some profit if you are holding it so why to sell this altcoin instead of others altcoin which has no potential of getting profit? (Just for pumping and dumping coin)
The best solution would be to add a stablecoin like USDT Tether and many people would use that instead and not have worry about the volatility of Bitcoin.
USDT is somehow stable but do you think that it wont be volatile later on? This is crypto market and we can't actually predict how the outcome are going to be