"Market capitalization is just a fancy name for a straightforward concept: it is the market value of a company's outstanding shares. This figure is found by taking the stock price and multiplying it by the total number of shares outstanding."

At least with bitcoin, there is no company. So, all it is is price * shares outstanding (held shares).

Given that there is some portion of btc that is 'lost' as well as the fact that we don't know what people paid for what is held, I don't see how anyone can come to a conclusion about the "the size of assets with different supplies."

In fact, the definition of market cap says nothing about that conclusion. The description says that it was just a way of grouping companies of various sizes. So, we are back at square zero, bitcoin is not a company.

Maybe I'm totally wrong in my feelings about MC, but at the end of the day, this is not an indicator I would use for TA or popularity of a cryptocurrency. For example, Volume is a much more interesting high level number.