20% Tata Sky won't be a problem. Check Rtings' burn-in test on 2017 series. Logos burnt-in at 3,000 hours or so. Prominently by 3,500. The red subpixel was the biggest problem. All pixels are actually white, and colored ones have filters on them. Red supposedly requires the pixels to drive higher, so they burn out faster. In 2018 and then again in 2019, red subpixel was increased in size, along with aperture ratio improvements. So you can expect at least 2x performance. There's also logo luminance from 2018 onwards. Worst case scenario, logos will burn-in from 6,000 hours on C9, as red subpixel is almost twice the size compared to C7. OLED panel itself in general should be good for 20,000-25,000 hours before blotchiness starts happening as compensation cycle runs out of headroom. Again, conservative estimate.
Now let's say you watch for 6 hours every day. That's about 2,000 hours yearly. Extra on weekends maybe so let's make it 2,500 hours. That's still a good 8-10 years before general degradation happens.
20% of that usage is TataSky, so that means 500 hours annually. 6,000 hours to burn-in means 12 years. More than enough.
Most probably, TV will die from some electronic part failure before burn-in happens in new sets. I haven't had a TV last longer than 4 years. Brother's 3D Sony TV died after 4. Family Panasonic LED TV died after 3. Replaced it with iffalcon, died after a year thanks to a buggy software update. Motherboard needs changing. Who knows when that will happen now.
You'll be fine with OLED for your usage, as long as you can afford it.
It's a joy to watch. Even old movies look spectacular, especially black and white movies with dynamic lighting. Heck, even Seinfeld looks good as there are so many night cars shots and what not. Only con is it being 4k, which means that it'll show compression in the sources too.
Mostly it's fine. I fall in love with it every time I watch it.