The Jetsons, Scooby Doo, and Teenage Mutant Ninja Turtles. (Files/HANNA-BARBERA, Warner Home Video/Reuters, PRNewsFoto/Nickelodeon via AP)

After these messages, Saturday morning cartoons will not be right back. At least not the way some of you remember them.

“The Smurfs,” “Scooby Doo,” “The Jetsons,” “Ghostbusters,” “Animaniacs,” “Teenage Mutant Ninja Turtles” and other cartoons of Gen X childhoods aren’t gone, but their dedicated time slot is. So what? kids these days might say. But the nostalgic among us remember a time when cartoons weren’t a la carte — and Saturday mornings were sacred.

This past Saturday, the CW became the last broadcast television network to cut Saturday morning cartoons. The CW is replacing its Saturday cartoon programming, called “The Vortexx,” with “One Magnificent Morning,” a five-hour bloc of non-animated TV geared towards teens and their families.

From the 1960s through the 1980s, Saturday morning time slots were synonymous with cartoons. Broadcast networks and advertisers battled for underage viewers. But that started to change in the 1990s.

In 1992, NBC was the first broadcast network to swap Saturday morning cartoons for teen comedies such as “Saved by the Bell” and a weekend edition of the “Today” show. Soon, CBS and ABC followed suit. In 2008, Fox finally replaced Saturday morning cartoons with infomercials.

In the 1970s and 1980s, a Saturday morning cartoon viewership could grab more than 20 million viewers. In 2003, some top performers got a mere 2 million, according to Animation World Network.

What happened? Cable, technology and the FCC.

Broadcast channels faced competition from kid-focused cable and satellite channels such as Disney, Nickelodeon and Cartoon Network in the 90s. They offered kids cartoons throughout the week, making the weekend less of a draw. VHS followed by DVD and DVR gave people the option to watch whenever they wanted. Nowadays, you don’t even have to sit in front of a TV to watch cartoons thanks to streaming services such as Hulu and Netflix.

The 90s also saw a shift in the type of TV geared towards kids — thanks to a Federal Communications Commission rule requiring broadcast (but not cable) networks to offer at least three hours of educational programming a week between 7 a.m and 10 p.m. The rule also limited kid-centered advertising during children’s TV programs, which made cartoons less profitable for networks.

Cultural factors may have also contributed to the decline of Saturday morning cartoons. Gerard Raiti, writing for Animation Network News, said the rising divorce rate put more emphasis on spending “quality time” with kids — doing things other than watching TV.

So is it the end of an era?

“It’s sad, though, that an entire generation of kids is missing out on lazy Saturdays filled with excellent cartoons,” wrotes Jessica Rawden of Cinema Blend. “Replacing them with cheaper, educational content was bound to happen, but a little magic has been lost in the process.”

But not everyone thinks the magic is lost.

“Saturday morning cartoons have never been better,” wrote the Los Angeles Register’s TV critic Michael Hewitt. “Cartoons for kids are at their peak. They’re far superior visually to the cheap productions of the past, and generally have much smarter scripts. They’re also finely tuned for a narrow age group, so little ones can enjoy ‘Pocoyo,’ preschoolers can swing swords along with ‘Jake and the Neverland Pirates,’ elementary schoolers can howl to ‘Sponge Bob Square Pants’ and the older set can feed their subversive needs with ‘Adventure Time.'”

These days, there’s also animated fare for adults, a genre that has grown popular as Saturday morning cartoons have declined. The last generations to enjoy Saturday morning cartoons aged into “South Park” and “Beavis and Butt-Head” in the 90s, followed by “Family Guy.” Then there’s Adult Swim: a non-prime time slot, albeit on a cable network, dedicated to a bawdier, nighttime version of Saturday morning cartoons for adults-only.

For the nostalgic, Slash Film has a roundup of the 20 best Saturday morning cartoons of all time.