Its simpler than that.

Flatscreen TV's have shitty speakers.

Just did a hearing test last week, still in the very good range.

The sound is mud, we've just become accustomed.

It's very easy to watch an older movie on the same system and notice the contrast.

Mid band hearing is the last to go, unless there's lot of loud noise damage.

There's a things called 'hidden hearing loss' in which the ability to pause midband sounds specifically in complex/noisy situations degrades. This is missed by standard tests, which only look for ability to hear a given frequency in otherwise silent conditions.

https://www.audiology.org/consumers-and-patients/hearing-and...