It really depends on the roads where you drive. In the Detroit area, the roads here are worse than in Afghanistan, so it's not uncommon to replace rims, struts, tires, shocks, and all kinds of other bits before the rest of the civilized world would even consider it. For conspiracy theorists, it could be a way to force people to buy new cars sooner, or maybe just the whole area is one big squeak and rattle test track.
I replaced my struts and shocks at about 115,000 miles, and they were still in good shape, but one shock was leaking oil, so the rears were done first. Then I thought since I switched brands, I should do the struts too. I even did it all myself.
I'd say 80,000 miles is a bit early, unless you drive 55 over speed bumps or do a lot of stunt driving.However, at that point there are less miles ahead of the struts then have gone by, so if you like the car and want to keep it, it's worth the upgrade.
Sometimes as well, if a strut was damaged from a big hole, the tire could have some damage as well. It would bear looking at, especially a front tire.
Jeff