I think It's hard to find a place to buy altcoin directly. I believe this is what makes Bitcoin and Ethereum particularly so great in terms of all other altcoins. As long as the system has to buy altcoin using bitcoin / eth, it is highly unlikely that altcoin will go beyond bitcoin, because there will be people who put as much money into BTC as they do.
It is an interesting opinion that I doubt many people in this forum share. Altcoin is generally just a bigger market, but for the most part, bitcoin is the bridge between them. Generally, if you want to buy altcoin, you should buy bitcoin and then use the bitcoin to buy alts.