Contacts wit many foreign carriers are breached. However, many of such carriers have learned the hard way by not violating T & Cs as they relate to:
Pay;
QOL;
Housing;
Medical;
Loss of License.
To name a few.
Carriers I've worked for from the early '90s were more reputable. I've noticed their willingness to breach contacts or change the T & Cs when there're was a glut of pilots. But on the other hand there were pilots out there willing to lower the bar such as the P2Fers, DECs who joined Ethiopian knowing they will be paid $60.00 per day until line training is complete.
Who knows perhaps the pendulum will once again swing back to the way things were in the '90s.