They're perfectly capable of implementing all the same search operators as 1990s Yahoo and 2000s Google. It's a solved problem.
The issue is that they don't want to. They'd rather be a middleman offering you "useful recommendations" (that they or may not sell to the highest bidder) instead of offering you value.
The issue is that they don't want to. They'd rather be a middleman offering you "useful recommendations" (that they or may not sell to the highest bidder) instead of offering you value.