Cars of the 70's & 80's had the same problem, where only minimal protection was applied to the underbody components, but because the body's rotted so badly too, most were scrapped maybe by 10 years old, so long before a suspension component ever became an issue
Nowadays, manufacturers have generally sorted the bodyshell protection, so at 15 years the parts underneath become an issue on cars. After all, no customer sees those bits when they're standing in a shiny showroom, so no point wasting money on decent protection....
A bit like our original rear arms, if they'll last 10 years, that'll do.