I bet it's excellent in a laid-back recliner

Well it's possible to retrofit, you need to be willing to open the wall which is not a bad thing as it allows you to make a frame so you can center the TV exactly where you want it.

There's no perspective without floor, but based on the shelves I'd say it's too high. A TV should be at roughly eye level from where you look at it.

Okay now show me a fireplace over a TV

While being over a fireplace causes the TV to sit too high, the real concern with that location is heat and particulate matter released from the fireplace.

I love my TV over my fireplace.

People are weird.

If it works for you that’s great. Every one I’ve experienced is so high up that it is literally a pain in the neck.

I suspect a minority of TVs over fireplaces are rarely used, or just used for utility (news, etc). Those ones are usually the worst ones where you question the sanity of placing it there.

Also, after pondering it more, I also suspect really large TVs up higher with a father back seating position are less of an issue. If you visualize that, the angle of looking up gets shallower the farther back you go.

The cliche of TVs over fireplaces being bad starts with smaller tvs many years ago. I suspect your situation is a reasonable distance back. And your tv is big enough to support that distance.

That’s true