Whilst its true all airlines are having staffing issues it does seem TUI are suffering more than most.
Interestingly I am aware of a number of staff working for other airlines who were with TUI pre pandemic. it may obviously work the other way as well but TUI do seem to have lost a lot of decent staff for some reason .
Its also noticeable that while all the sub chartering is going on using other airlines there are a number of TUI aircraft inactive. BHX for example has a Sunwing ex TUI 737 arrived back from Canada which hasnt moved for about 5 days whilst they are using Air Tanker and Neos amongst others to cover delays,
Hopefully now we are getting in to main season these issues will start to settle, but the brand image is definitely suffering at the moment