My wife and I left fi for exactly the same reason as the blog post. My wife had a problem with her pixel 2, and she was pretty much without a phone for WEEKS. We absolutely adored fi for years before that. We were huge advocates. After we had such a horrible experience being gaslighted, promised, and let down we just fuck this and went to AT&T. It’s not like we love AT&T. In fact, we don’t. But you know what we can do? We can walk our asses in a store in pretty much any city in the country and leave with a phone.
If customer support is important to you, I heartily recommend giving Ting[1] a try. They're a T-Mobile and Sprint MVNO. Every interaction we've had with their customer service has been excellent. Last I called, there was no phone tree, just a person immediately picking up (hopefully it's still like this).