Senior people in your industry are often more willing to give time and advice than younger professionals expect. The mismatch — they're often available; juniors don't ask — produces wasted potential mentorship.
How to ask well
Specific, brief request. 'I'd value 30 minutes of your time to discuss X specific career question.' Not vague 'pick your brain'. Specific question shows you've thought about it.
Most senior people respond positively to thoughtful requests. The worst response is 'no, sorry'. The downside is small; the upside is potentially transformative perspective.