When it comes time for layoffs, it generally isn't what your boss knows, it's what your boss's grandboss thinks to throw onto a spreadsheet at the eleventh hour before Quarterly Reports are due.

A good direct boss might keep you on track for a bonus or other "local advancement", maybe even a promotion, but many companies you are only as valued as the ant numbers you look like from the C Suite's mile high club. (Which doesn't protect your good boss, either.)