In days of yore they were made into wine. In some rural areas children would be given a day off to help their parents gather enough cowslips to make the wine.
The leaves may be eaten raw in salads (although I haven’t tried them) with a slightly bitter taste. They were and maybe still are used in medicinal herbal remedies.
Above all they are pretty and an early source of nectar for foraging bees.
Yesterday I sat and watched a bumble bee collecting nectar from nettle flowers. Maybe a good excuse to leave the nettles where they are.
gfreedmanblog 
When l was growing up Gill, cowslips were known as peggles. I still tend to call them that xx
What a great name. I never knew them before I moved here none in St John’s Wood where I grew up!
In the village where l grew up they grew wild everywhere
I certainly see a lot by the roadside and walking across fields. So pretty