Pretty good advice on here, and I've been helped several times over the years, but here's my story, just to balance it out.
I have a 2007 Tahoe LS, bought it in 2017 with 147K miles and it had regular maintenance...it was a state vehicle. 5.3L flex-fuel WITH AFM. It was my daily driver until I retired in late 2021 with daily 110 mile round trips, plus several runs across country over the years from CA to TX, KS, WA, and MT. In addition I used it to respond to large fires all over CA, so it went EVERYWHERE!
Once I retired, it doesn't get driven as much, but it's still my primary driver. It currently has 320,000 on the original engine, and after turning off AFM and fixing a leaky oil pan gasket a few years ago, I'm not losing any oil.
The 5.3 is a solid motor if you get a good one and (I stress this) do proper and regular maintenance. Your mileage may vary, but they can be a solid ride. Good luck!