For many years, Netflix executives bristled at the notion that the company really had a rival. Not Hollywood powerhouses like Disney, nor tech giants like Amazon. Instead, Reed Hastings, the company’s co-founder, insisted at one point that Netflix competed with people’s desire to socialize, or to go to sleep.

But there’s no hiding from YouTube.

Netflix and YouTube are increasingly locked in a fierce battle for control over the television set, a rivalry that even Netflix’s executives can no longer deny.

“That was more of a fun narrative than it was, you know, the brutal truth,” Jason Kilar, the founding chief executive of Hulu and a former chief executive of WarnerMedia, said about those past comments. “The brutal truth is that YouTube is indeed the biggest competitor of Netflix at this point.”

The rivalry signals how the streaming wars have entered a new phase.

For years, increasing subscriber numbers to their streaming services was the ultimate goal for media companies. Now, those companies are trying to increase the amount of time viewers spend on their service. On that score, YouTube and Netflix stand above the competition.

The two accounted for 20 percent of all television viewing time in the United States in May — 12.5 percent for YouTube, 7.5 percent for Netflix, according to Nielsen. The next closest streaming competitor is Disney, whose multiple streaming services (Disney+, Hulu, ESPN+) together accounted for 5 percent of TV time in May, Nielsen said.

And YouTube’s lead keeps getting wider. Two years ago, YouTube’s share of TV time was roughly half a percentage point higher than Netflix’s — now it is five percentage points.