WordPress, Nextcloud, XWiki, Univention, Passbolt are a few other profitable open source businesses doing well. It is possible to sell open source software :-)
Now, maybe it's not as profitable, but not every wants to be as big as Apple or Microsoft.
It’s not very clear to me what the exact funding model is, but I don’t think if Jetpack went away it would make a seismic financial dent in WordPress.org.
A lot of that sponsored core development comes straight from Automattic, which gets revenue from WordPress.com, WooCommerce paid services, Tumblr advertising, and Jetpack too.
