What Select reverse has said is absolutely true.
Careers progression in ops/crewing is very limited, but is great fun...you are very much at the sharp end making it work.
There will always be more opportunities in ops.....crewing is too specialised, but to really advance with an airline most of the top people have a marketing/commercial planning background.
Get into the commercial side of the business to go right to the top.
Ops/crewing for the fun time and experience, but DO NOT stay too long.