My last 6 return trips GVA-LBA in the last 6 weeks with jet2 (and 10 or so other jet2 flights in the last 18 months) have all been fine. Good crew, none of them immature even though some have been quite young. I think you were just unlucky with your experience.
Not used TCX for years, so cant really comment.
FRNikolai - To ballance things up, I have taken only 2 Ryanair flights and both were equally the worst experience I have ever had flying, so have not and will not ever use them again - they had their chance. But at least I tried them and can compare them to others.