This may be true for the non-serviceable hub type bearings. The seals wear, the grease gets old, and they can get kinda funky after high miles (>120K?). But for the old style repackable double tapers, where they can be regreased and new seals put on, they can go a long time with proper care before replacement.

Automotive wheel bearings typically fail because of improper installation or contaminant intrusion past the seals (water and dirt). They rarely fail from old age. (In technical terms old age typically means excessive Hertzian stresses that degrade the metal itself.)

When bearings are serviced, the races should be nothing less than perfect. If there's any denting, frosting, corrosion, or discoloration on the surfaces, the set (inner cone, rollers, and outer cone) must be replaced.

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95 E320 Cabriolet, 169K