I did the same at my house. My samsung that is 5 or 6 years old was getting glitchy with the apps. Firesticks solved it. I have a few of them.

^^^ The picture quality sure didn't lose anything by using the Firestick....I'm happy.

The Vizio 65 that I bought is an E series, a display with smart cast.
While Vizio did eventually send down updates with current apps, and essentially turned my display into a smart TV, we almost always find what we want to watch on our phone/tablet and cast it to the Vizio.

Yours might also have the smart cast feature, which would negate the need for a firestick and Vizio installed apps.

I have my ethernet hard wired and wifi connected to the TV, and also paired to our phones/tablet so if the internet does crash, we use mobile data.

I only notice bad quality with Prime football games. It's getting better though, and will be perfect when they allow a mute option for Al Michaels.

My 65" is a D series and it does not have smart cast. (prob why it was only $998)

I know that when I bought it...it came with 4 diff apps. Within a few months, there were over a dozen that the tv downloaded. More and more added...ones that I have no interest in.

The last time I watched Prime football, the video was much better than the first ones.
But they haven't mastered the audio...sounds like it's in a big tin can.

I'd check to see if they upgraded yours free of charge. It may have been built for Bluetooth but no software installed. Try to pair it to your phone.

^^^ I guess I don't understand. Why would I want to pair my phone to the tv?
It's working fine with the FireStick.