People are leaving BA. Of course there are those who retire and those who lose their medicals etc, but there is a small flow of people who decide BA is not for them. Some of these come from LH and some come from SH. I know directly of 2 FOs who decided the 744 in BA was not for them and quit to return to their previous employers. I’ve heard of a couple who got their command on SH and who’ve left to earn a lot more cash. I’m not sure how it was 10+ years ago, but BA certainly isn’t what it used to be. That said, I would rather look at the sun through a pair of binoculars than return to my previous employer (Jet2). But, everyone is different....