I've known or known of lots of pilots who fall/slip/choose or are pushed out of flying for a living. Unless you're one of the fortunate few then a good job is by no means a certainty. Whilst airlines are seen as the most obvious part of aviation they're not necessarily the largest employer.
Pay & conditions is very low at the piston GA end of the industry with a gradual rise the further away you get with a comparitively exponential rise as a jet captain.
Many times one's employement is shaky. Retrenchments, furloughs, bankruptcy etc. 'Casual' employment (paid per hour flown) but you're required to be present the whole day/week and usually expected to do work related activities while there eg answering the phones. Rosters that conform to the letter of the law - if you're lucky - but not the intent. Middle or senior management who put pressure on the pilot to 'get the job done' irrespective of the illegality. As long as such things aren't recorded then they can't be proven. Annual leave that's accrued on the basis of a 5 day working week - but used up on the basis of each day away is a potential work day & therefore credited against one's leave entitlement.
Such is the lot if you don't strike lucky and end up in a (reputable) airline.