BA short haul without bidline is just easyjet with a different uniform & a significantly longer time to command.
And if you are 30 plus and choose the longhaul route there is a real possibility you will retire as an FO. Nothing wrong with that of course, but as an FO myself with a command spot in sight I'll take the command first then join BA as a career FO.
This post does come across as bias, but I don't work for easy and I've passed the BA selection twice before drowning both times.
Just my 2 cents