So since the start of 2017, 380+ new shitcoins have been added to the list (as tracked by coinmarketcap.com). The list went from ~900 to ~1281 cryptocurrencies. And 6581 "markets", whatever the hell that means.

So Bitcoin's % dominance as tracked there is not being 'eroded' by other alts supposedly taking market share away. It's being eroded % wise because of all the shitcoins merely being added to the ever growing list.

In other words, just by virtue of adding a new shitcoin to the list, Bitcoin's % market share of the total is shown to go down. Because the individual fiat market caps of each new shitcoin added are fakery. Complete bullshit.

A more accurate way to track % and total market share would be to restrict the list to say the top 500 by market share, and anything below that gets taken completely off the list.