@CoolArrow
Hey, I'm new here but I thought I'd chime in as I have 5 different 75"+ Samsung tvs ranging from 2019 up and at least 2 of them are basically on 18 out of 24 hours a day haha...
First I'd say if your TV is flashing the backlight it could be a couple things I'd try before tossing it out... swap the HDMI cable first off and if that doesn't work believe it or not a firm smack on the back of the panel in a few areas can sometimes do the trick as the ribbon cables in the back can come loose on the edges over time from heating and cooling regularly over the years. Sometimes even just leaving it unplugged over night can do the job as well to discharge the system and allow it to kind of reset itself.
Short of that... have you considered looking at Hisense at all? They seem to have tvs with all the bells and whistles you'd want and fairly priced for size especially compared to Samsung. They also have a package deal for a all in one short throw laser projector setup with up to 130" 4k display. Little box only about 10 inches from your wall in front projects a beautiful theater screen and it's under $4k Canadian.
I think the major brands are basically the same in quality these days but the up and coming brands have something to prove to stay competitive on the market so don't discredit TCL/Hisense for what they have to offer. Even Amazon has Qleds now that seem to be decent with full array local dimming so you have tones of options.
4k/8k... I have both in my house and 8k is sharper for sure plus color and brightness... but still too expensive for the "wow" factor you get. I wouldn't recommend it unless the absolute best picture is all you are looking for and need that 85"+ display to be better than the neighbors. it really isn't worth the cost when you can find very good 4k giant screens at better prices these days full of all the features people love.
Personally at 85"+ I'd strongly suggest the projector route (laser or standard) but if it's a screen you need keep it simple in your head...
OLED for blacks and contrast/movies
QLED for brightness and color/day viewing
HDR10+ or Dolby Vision? Both? Hisense/TCL for the money
Best motion control sports and gaming day viewing?
Samsung
Best 4k color accuracy/clarity night viewing?
Sony
Great at all, expert at none?
LG
Sound? Please use a home theater/sound bar (sonos) if you're spending on a nice TV setup don't castrate the audio with TV speakers haha... but I think Samsung/Sony/TCL have the best TV speakers of the bunch if that's what you're going to go with.
Hope that helps somewhat
Cheers
