Just to clarify this slang expression. ‘Ability to fog a mirror’ means as you exhale a mirror held by your nose will get foggy. In other words, the base requirement, besides hours and ability to work (green card, etc.) is you must be living, not dead. No higher requirement. Okay, that is a bit simple. If you are a convicted murder, you will not get hired.

As others have said, the ability to pass training is more stringent. It has not changed (although many airlines will give a new hire more sim training). As the standards to be hired for training (Conditional Job Offer - CJO) has become lower yet the training standards have remained the same, there are more failures during training. This is not a surprise.