The advent of streaming and video on demand has hastened an inconvenient and often downright unseemly devolution of “channels” and what they used to mean to the TV consumer.

The long-established “evolve or die” desperation of basic cable/dish meant that refreshing programming onn legacy channels in the search of a larger audience, or luring back an audience that strayed led to godawful “mission creep” for channels that we’d come to treat like info/entertainment utilities.

The Weather Channel was “always there” to let us know what to prepare for in our own world on any given day, with a dash of “white out” blizzards, deathly freezes, hurricanes, floods and tornadoes in places that many of us fled (Alaska, North Dakota and Florida), making us glad we did or relieved that we weren’t living there.

But if you can’t sell enough ads to keep people connected longer than “I don’t need a raincoat/need to take in the plants for a frost today” you start producing low-production-value weather documentaries, series and the like. If you can’t make your bottom line with the odd Jim-Cantore-standing-in-a-hurricane event, you start hyping your own events — doing your own storm “naming” and the like.

AMC started life as American Movie Classics. First the “American” movie labeling went, then “movie,” and “classic” until assorted series — too many of them built around zombies — became their bread and butter.

The History Channel was likewise pretty good at what they did at the outset. There are legions of legitimate historians with non-fiction books worth adapting into documentaries and PBS and “The American Experience/American Masters” can’t get to them all.

But then they realized people were nicknaming them “The World War II Channel.” The accountants told them that older demographic that was watching could only buy so many pills, therapeutic socks, footbaths and sciatica cures. So they went “Ancient Aliens” and turned the network into a series of freak shows filled with pseudoscience and pseudoscientists. Legitimate historians, by and large, avoided becoming sons and daughters of Erich von Däniken and avoided that garbage.

Ghost hunting and paranormal shows came next, often with a dose of Shatner included.

Their impartiality vanished as well, as agenda-driven, mass production/low-production-value assembly line docs seemed sponsored to publicize aspiring Republican politicians, virtually none of them “expert” on anything, much less say “The Gilded Age” robber barons whom one series claimed “made America.”

The cost of all this was legitimacy. You might not have drawn a crowd with Sander Vanocur hosting “Movies in Time,” interviewing historians about a movie depicting an historical event, fact-checking “Titanic” or “J.F.K.” But you didn’t embarass yourself or torch your brand in the process.

Even their legit history seemed over reliant on not-quite-my-field historians from lesser known institutions. Can’t find an expert on this or that? Contact the same telegenic regulars you use from The University of Kent or Kenyon College and let them bone up on punchy answers to pre-submitted questions.

But “Kevin Costner’s The West” and the Lebron James-produced “Jim Thorpe: Lit by Lightning” are stand-out productions packed with real historians and legitimate sports experts.

No ghosts or ghost-hunters, no fringe freaks riding the flying saucer circuit — just Mr. Integrity, Costner, hosting eye-opening recollections and recreations of “Bleeding Kansas,” which lit the fuse for the Civil War, “Johnson County Wars” (the basis for the Western “Heaven’s Gate”), balanced accounts of Indian conflicts and “erased” historical figures like Joaquin Murrieta, “The Robin Hood of El Dorado.”

And the authors and historians are mostly top-drawer, headlined by Doris Kearns Goodwin, the dean of American historians. It’s eye-opening and a long-overdue realization of what any “History Channel” series should be.

Native American filmmaker Chris Eyre (“Smoke Signals,” TV’s “Dark Winds”) was an excellent choice to bring Jim Thorpe’s story to the screen in a documentary. Leaning on Thorpe’s unpublished autobiography, a few recreations and historians who know their stuff when it comes to America’s treatment of Native Americans, Indian Boarding Schools and lingering cultural racism, as well as Olympic athletes and some well-known sports reporters, Eyre renews our connection with a singular figure, one of America’s first sports superstars.

If The History Channel’s proprietors have any interest in burnishing their brand — and they should, considering the piffle they’ve been packing their schedule with — that documentary and Costner’s series should be their template, a gold standard for who they get in business with and the lofty goals of reporting on “real history,” American and otherwise, inconvenient truths included.

Over the years there have been glimmers of hope — the odd stand-out show or one-off documentary — that suggested that the folks running this tent show remember what they’re supposed to being down, over the years. But a 24 hour broadcast day means there’s always room for flying saucer filler and the like. It’s no wonder Americans have turned so cynical about “facts” and agreed-upon truths. Even allegedly impartial, cold-hard-facts television has embraced snake-oil selling with a vengeance.

But if we tune in for these new offerings, maybe the numbers will convince them that repenting and sticking to facts pays off.

There’s long been a pronounced gap between the history produced on PBS and the boilerplate, formulaic docs cranked out for The History Channel. It’s time that gap narrowed, and maybe with these productions raising the bar, and a little “Let’s steal that ‘History Detectives’ concept now that PBS is done with it” and the like, The History Channel can be “saved.”