TVs were always cheap compared to cost to make the things - it's not just the "oh, they have advertising now" thing.

Source: I worked in electronics retail in the late 80s/early 90s, and in one of the world's largest consumer electronics firms when my career proper started.

The TVs in the window of the local electronics chain store (or in Walmart) were sold at practically zero margin, or more often than not at a loss. The retail chains would basically hold a gun to the CE companies heads and tell them if you're not willing to sell at a loss, nothing you make is going in the window display, or worst case we're not selling you at all.

The retail chains didn't care because all their profit was in selling accessories and unnecessary extended warranties. The CE companies hoped that they could make it up by selling you the more expensive model they actually made a profit on once you were in the door, or by selling you a VCR or whatever as well.

This is why the TV companies were always looking for a "next big thing" (flat-screen, ultraflat, widescreen, HD, 3D, 4k, 8k...) to differentiate the "next model up", which is to say the model the store would actually allow them to make a profit on.

This particular race-to-the-bottom mutually assured destruction business model is also the reason there is practically no consumer electronics manufacturing left in the West, of course. And why manufacturers grasp at stuff like advertising.