Lots of violations of this law (which applies to any person employed in Washington State, even if the employer is out of state) in the HN 'who's hiring' thread, provided >= 15 employees.

What is the specificity of the range? Can someone publish a meaningless and wide range that does not effectively serve any purpose and be compliant?

No. WA LNI provides further guidance under Chapter 6 [0].

> The wage scale or salary range should provide applicants with the employer’s most reasonable and genuinely expected compensation range for the job.

[0] https://lni.wa.gov/forms-publications/F700-216-000.pdf