Streaming video services such as DirecTV Now may have “scary implications” for some programmers, who could see some channels left behind, and operators, who might lose subscribers. But they shouldn’t take a big bite out of Comcast, CEO Brian Roberts told investors today at the Morgan Stanley Technology, Media & Telecom Conference.

“Our view was that scale matters,” he says. “When we just owned E! and Golf Channel and Comcast SportsNet, it wasn’t enough. Now we have MSNBC, CNBC, USA, Syfy, Bravo — that’s a hell of a footprint.”

He acknowledges that the business will see slower growth. “Ratings have come down, with all of the competition.”

But Roberts says that’s been offset by the stronger-than-expected growth in other fields in the six years since Comcast bought NBCUniversal.

“We didn’t count on theme parks at all,” he says. “Broadcast had no [retransmission consent] fees when we got there. And film was not with the momentum it has now.”

Speaking of the Universal Studios, Roberts says that it has “a strategy that’s sort of like a portfolio.” That includes about nine franchises such as 50 Shades, Fast and Furious, Despicable Me, Pets, and Jurassic World. “Those are pretty good bets.”

Universal also is high on animation — which Comcast markets across virtually all of its properties.

That led to last year’s acquisition of DreamWorks Animation. The benefits won’t be immediately apparent, he says, because “unfortunately it takes about four years to make an animated film.”

But “those characters in our theme parks, television specials, consumer products, video games — that’s how it all works. And that’s why DreamWorks fits as well as it does.”

Roberts also talked up the agreement, announced this morning, to add YouTube to Comcast’s X1 platform.

“In a few seconds you’re going from [Netflix’s] Stranger Things to [NBC’s] This Is Us to exploding watermelons,” he says. “That’s sort of our vision of how to keep innovating. And we’ll keep being that aggregator of aggregators.”

The ability to call up videos with a voice-controlled remote control makes the experience “completely different.”

For example, a command to call up NBC’s The Voice would also give users the option to see the show’s stunts and promotions on YouTube. In addition, users also could ask for something broad — for example, cooking shows — and find results across the traditional cable platform and digital services including YouTube.

“A couple of thousand people have been working on this innovation for a decade to give us what we think is the premiere experience in the world on interfacing with all of this content,” Roberts says.