I've seen plenty of UK job listings that don't state the salary? Meta for example posts a salary range for their US jobs (https://www.metacareers.com/v2/jobs/1651941818579349/) but not UK ones (https://www.metacareers.com/v2/jobs/2274967272693600/). There are some fields and roles where it's expected in the US as well, and I suspect that's just where the difference comes in.

Without explicit salary ranges, the market functions through implicit cultural expectations about what an appropriate salary should be. Which of course has a lot of problems. For example, US software engineering salaries are stereotypically bimodal, and one of the staples of our mid 2010s job market discourse was people who'd only seen one hump insisting that the other can't possibly exist. (The question of whether there's actually two humps or just a wide range, I don't know if I've ever seen resolved.)