I like the way my navigation works too. I know some people complain that it's not accurate enough, or that it takes weird routes but these complaints are common across various navigation tools not just the built in nav.
I think it's a matter of what you're used to. I like Garmin nav, but I've got a friend who uses Apple for everything and will only navigate with his iphone. I have another friend who swears by his TomTom. I don't think any one system is any better/worse than the next.
As for built in nav. I specifically order my vehicles WITH it because I like the way they work, I've got a giant map available at all times, and I don't have to screw around with my phone. As for paying for service. I don't bother. The majority of the features still work, you just lose the traffic updates. I don't live/drive in congested areas so that's not really an issue. If I run into unexpected traffic, I'll turn onto a side route and let the navigator automatically route me around what I just avoided. It doesn't have to know the traffic is there, I can see it and make my own detour.
I've used a Garmin device for years and I don't have an issue with the operation of the built-in NAV. However, I absolutely despise having to pay for map updates when maps on my phone get updated for free. I live in an area where new streets are added every month and my work takes me to new areas all the time. The built-in NAV is useless then. As a result, I prefer to use CarPlay in most cases, but may flip on the built-in every now and then.