Newbies are safer with bitcoin, and avoiding altcoins altogether.
Marketcap is a meaningless statistic. I could create a new token right now, print 1 billion of them, sell a single token to my friend for $10, and now my market cap is $10 billion and I'm the third "top" coin. Just because an altcoin is in the "top 10", means nothing. At least half the coins in the "top 10" are literal scams.
The Coinmarketcap list will be updated by liquidity pool. Volume can be increased by fake or scam exchange help, for this effect any coin will be listed in the top like Tagz exchange. Not only newbies, we should all buy Bitcoin or top coin to protect our money. I think that's how the market won't be meaningless statistics.