Usually, you'd be talking dampers (often called shock absorbers in the UK), and often the springs will have broken.

Having said that, I remember that 20 years ago, those kinds of parts would need to be replaced after maybe 60-80k miles. However, everything seems to be better built now - my van has 214k on it, and no sign of needing replacements - same goes for all the cars I've bought and sold (20 or so) in the last 3 years.

It's pretty commonly for shocks/struts/dampers to be worn out by 50-80k miles. As early as 30k. Sure, the car will still seem to generally drive fine, but the point is that all of these things get worse over time.

Further on down the mileage line, virtually everything is wearing out. Rubber bushings in control arms. Rubber bushings in all your rear suspension points. There's rubber EVERYWHERE on cars, and it all wears out. Motor mounts, transmission mounts, shock mounts. Again, it'll still go down the road, but it won't drive like new. You might have a lot of slop in steering, slop in cornering. The car might pull one way or another under acceleration. It'll be louder, harsher, clunkier.

You at least need to do struts and shocks, probably springs if they're separate. You'll want to check the strut towers are still decent, or if they need reinforcement.

Going a little deeper, probably your tie rods and sway bar links are shot, as are the control arm bushings (which may or may not be integral with the entire control arm).

Primarily the shocks / dampeners and their rubber bushings.