Typically, italic formatting indicates gentle emphasis, bold formatting indicates strong emphasis. Given this, * and * make sense. However, typically people use _ for gentle emphasis in Markdown, which makes _even more_ sense. Be careful not to confuse specification of rendering,
As for - and >, they've been in use in plain text email clients for bulleted lists and quotations for 35 years now [1].
I'm not confusing anything. I'm saying that the example I provided is not intuitively recognizable as a block quote. And it gets worse when you have more nested decorations.
I'm not sure I agree *something* is intuitive for italic and **something else** is intuitive for bold, or that this is intuitively a block quote:
> #### The quarterly results look great!
>
> - Revenue was off the chart.
> - Profits were higher than ever.
> > Everything is going according to *plan*.