Everyone can afford to invest in Bitcoin. If they can invest into altcoins, there is no reason why they cannot do the same into Bitcoin. If they have a hundred USD to invest in Ethereum or Tron, they can also do the same with their USD to Bitcoin. I am not an expert but if there is one coin that is the best among all thousands of cryptocurrencies it is Bitcoin no doubt.
so, the right thing "if anyone can afford Bitcoin, they can afford altcoin too"
if we have money (maybe more than $10), then we can buy BTC and ALT, just different amount
for altcoin, personally I just prefer top 10 altcoin. They are already 'trusted' coins
higher liquidity, higher community, good use case, etc which is not others coin have