They're probably fine if they pass the bounce test ....should be up, down then settle.
The function of a shock absorber (also known as a damper), is to damp out the oscillations of the spring as it compresses (over a bump) and then releases that energy as it rebounds.
Without the damper, the spring would just go mad and the car would be almost undrivable.
I was changing the front fork oil on my old BMW K75, and with the drain plug out, you just bounce it up and down on the springs to expel the old oil. Once the oil was out, the bike was unrideable over a short distance as the handlebars just bounced up and down with obviously no damping
Here in Wiltshire, it's very noticeable that large "undulating depressions and crests" seem to have developed in main roads over the summer, probably due to the clay beneath drying out and shrinking due to the lack of rain. There are a couple of places which even makes my mudflap scrape briefly along the ground .... and this on an A road. The lanes are much worse.
