Mega-peeve

I freely concede: my hearing isn't what it once was. That doesn't, IMO, explain what I'm about to gripe about. To wit:

At least the PICTURE improved

Dialogue on TV and in movies has become challenging to follow. With streaming, it's easy to watch (or re-watch) shows and movies even decades old -- and those, as well as shows and movies just a few years old, I hear without difficulty. (In all cases, I'm listening through a modern audio system, with 5.1 Dolby surround sound. Stereo soundtracks, of course, don't make full use of those 5.1 channels.)

Why has dialogue become difficult to parse in so many recent productions? Is it:

• sound mixing that prioritizes special effects over dialogue clarity? 
• directors who can't be bothered to require a clear speech channel?
• some inherent flaw in the Dolby 5.1 technology (one that doesn't impact old-style, stereo soundtracks)?
• actors who can't be bothered to enunciate?
• directors who can't be bothered to require their actors to enunciate?
• the trend to make all dialogue super-snappy fast (a cynic would say, to squeeze in more commercials)?
• many -- or all -- of the above?

Assuredly, some of the above are at issue, because -- I repeat -- I can watch older shows and movies with none of the difficulty of the newest ones, using the same AV setup in all cases.

The next time I feel the urge to rant: TV and movie plots dependent on the audience reading in about a nanosecond (often tiny) text messages and caller IDs flashed across a character's phone.