Is a total stock index fund in the USA better?

A total stock index would be a measure of the stock available in  every public traded
company.
A total stock index fund would hold a large amount of stocks that are publicly traded in the USA.
This may have the impact of widening losses or reducing them because there is a wider spread of
 the risks involved than say focusing on a select 3 funds available in that index. A total stock index fund might consist of a portfolio that contains all the valuable stocks.