"Household name" can be tricky to define. If we stay in SFF book circles, it's easy to say that Brandon is a household name. If we go outside that, not so much.
Anecdotal example: amongst my group of friends and acquaintances, everyone knows about George R R Martin, J R R Tolkien and Stephen King. Only three know about Brandon Sanderson and that's because I introduced to them to him. Only one of those might be remotely interested in the Kickstarter.
In other words, there's a very strong case that Brandon isn't a household name that does not contradict what he has achieved.
Also, as far as him being slow with Cosmere, he's acknowledged that himself and a worldwide pandemic shutting the world down giving him time to write some unplanned Cosmere novels does not negate that or even change the current projected timeline of his main series Cosmere.
That later point is just me being a stickler, it's not a complaint against Brandon.