I usually reply to the brush-off with "I only ask because the seniority level is reflected in the salary, not the role or the advertisement."
I say that because it is, in fact, true: the seniority/skill required for the role and duties/responsibilities dictates the pay, the bullet points in the advertisement and the role description is often completely divorced from the level of seniority or skill required in the actual role.
IOW "We're hiring a Senior dev" might have me respond "That's a Junior pay-bracket".