I agree with your sentiment. Focus can search an exclusive list which contains multiple sites.
However, I search single sites. And I can recreate that experience even on mobile by visiting a given site and typing any search operators.
I never thought to try, but, for reference, it is apparently possible to search multiple sites with the proper operators.
guns (site:pbs.org/newshour OR site:bbc.com)
https://duckduckgo.com/?q=guns+(site%3Apbs.org%2Fnewshour+OR+site%3Abbc.com)&df=2022-05-22..2022-05-30
https://www.pbs.org › newshour › nation › how-does-u-s-gun-policy-compare-with-the-rest-of-the-world
How does U.S. gun policy compare with the rest of the world?
The United States, with less than 5 percent of the world's population, has 46
percent of the world's civilian-owned guns, according to a 2018 report by the
Switzerland-based Small Arms Survey ...
https://www.pbs.org › newshour › nation › governors-divided-on-gun-control-mirroring-the-nations-partisan-split
Governors divided on gun control, mirroring the nation's partisan split ...
Scott signed a law in 2018 limiting the capacity of firearm magazines and
raising the general age to buy guns to 21, with exceptions for 18- to
20-year-olds who undergo a firearms safety course.
...
https://www.bbc.com › news › 61599697
Texas shooting: US gun control claims fact-checked - BBC News
The issue of controls on gun ownership is being debated in the United States
once again, after a gunman opened fire in a school in Uvalde, Texas, killing
19 children and two teachers. US ...
https://www.pbs.org › newshour › tag › police-response-to-uvalde-massacre
police response to uvalde massacre | PBS NewsHour
Politics May 30. Watch 8:40. Tamara Keith and Amy Walter on the debate over
guns after the massacre in Uvalde. NPR's Tamara Keith and Amy Walter of the
Cook Political Report with Amy Walter join ...
https://www.bbc.com › news › world-asia-india-61629133
Sidhu Moose Wala: The murdered Indian rapper who 'made sense of chaos'
Drawing heavily from the genre of gangster rap, his music was a jumble of
gritty opulence - measured in guns and fancy sports cars - as he made sense
of life around him. His songs offered ...
@Josh, I was able to get the same result for exempli gratia.