Many years ago my opportunity to be join BA slipped away due to external factors beyond my control. I ended up in a decent leisure carrier that was unfortunately run into the ground and had a checkered flying career since financially but actually look back on it and can not complain because despite the much better financial stability I would have had in BA, I've had a far more interesting career and life experiences than BA would allow. On saying this, I would not move from BA with some seniority to work for Jet2 or the likes, rather I would only make a radical move if you decide to jump or stick with what you have and make it work as best you can.