I've been applying for ten years, never passed the final interview (which I made on a few occasions) but got darn close and on one job nearly got down to last handful of hundreds (that was for an apprenticeship which involved driving).
Maybe it's not what im destined to do but I'll keep applying for as long as it remains a goal of mine. I don't think this is one of those situations where getting disheartened and moving on is an option because the numbers quite frankly are against you. Even if you're suitable. I don't think, because of the numbers involved, you can interpret not passing the final interview a couple of times as an indicator of suitability. But if you keep making interviews somethings going to plan somewhere.
My advice does vary as to why this would be your final attempt, is it because you dont think you'll ever make it? got to be in it to win it. But it's not a nice feeling, I actively push two careers elsewhere whilst I 'wait' because part of me also acknowledges it might never happen. Personally I do CAD and repair machinary in the mornings and run my own little vehicle workshop in the afternoons, keeps me out of trouble so you can't let life pass you by either. But anytime a vacancy comes up at a TOC i feel I could work for an application goes in. Can't give up in this game IMO
Just my 2p not sure if its aligned with what you were getting at.