I have a similar set up to you - LG C2, and Sonos Beam.
I've had the Shield Pro 2019 for a few years now and if it broke I'd go straight out and buy a new one tomorrow. Pound for pound it's the best tech investment I've ever made. I don't know how it compares to newer boxes, but it's head and shoulders above everything I tried before I got it (various boxes, various chrome casts, even a Raspberry Pi). It has never let me down. The fact that it's still selling at it's original rrp after five years says a lot.
I believe there's no plans to launch a new one. But I'm not sure how the current one can be improved on.
One flaw is the latest version of Google TV which it runs by default. This serves you ads, which I can't abide, but you can install third party launchers (without rooting or other faffing) to avoid this.
And you'll probably also want to set it up as a Plex Server, which entails a moderate degree of faffing.
So yeah, two thumbs up from me.
[Edit] And it (and most good quality android boxes) will always beat a smart TV. Even if you're just streaming Netflix, Disney, etc. the interface and speed will be far superior to what your TV can achieve. And it can play locally stored files (procured through entirely legal channels) which your will TV struggle with.