"Sales fix everything" is a shortcut for "There are many experienced people who can help fix most problems your company is currently struggling with, and if you give them lots of money they will help you win.". You can throw money at most issues in HR, retention, brand, marketing, government issues, customer support, engineering speed, infrastructure. Of course, it is possible to hire stupid people who will hurt you, but we can assume basic competence on behalf of the successful entrepreneur and that she can find competent helpers.
In business, if you have a product nobody wants, you generally fail. If you have no means of capitalizing your company, you generally fail. But if you turn the product into a money-printing machine, you will resolve other problems with enough iterations. Sales momentum does not make your startup immortal but sets the company on a better trajectory than another startup with amazing culture, great passion, but no customers/revenue.
I've also seen companies that are such a complete mess and have such terrible product that they should just die fix everything with sales.
I worked for one that (on average) spend 950 euro to sell a 1000 euro product that isn't worth 5 euro. (It was extra "funny" since I just gave up trying to "sell" a similar vastly superior product for free. "Suspiciously cheap" was my potential clients verdict 99% of the time. After all, from all angles, every day of the week, they were offered the same product for 1000 euro!) I never sold anything working there but that was perfectly normal.
In business, if you have a product nobody wants, you generally fail. If you have no means of capitalizing your company, you generally fail. But if you turn the product into a money-printing machine, you will resolve other problems with enough iterations. Sales momentum does not make your startup immortal but sets the company on a better trajectory than another startup with amazing culture, great passion, but no customers/revenue.