In recent weeks, the absence of two high-profile new streaming services—WarnerMedia’s HBO Max and NBCUniversal’s Peacock—from streaming devices made by Roku and Amazon has shown how important the two tech companies have become as media gatekeepers. That clout might not last, though.

Streaming-video devices are losing ground to internet-connected TVs that have streaming apps built in. The percentage of broadband-equipped U.S. households with these smart TVs reached 54% earlier this year, up from 47% a year earlier, and well above the 42% share held by streaming-video devices including Roku, Apple TV and Amazon Fire TV Sticks, according to Parks Associates. That gap is likely to keep growing: The Consumer Technology Association projects that consumers will buy 35 million smart TVs this year, compared to 22 million streaming devices.