Three-Cornered Leek - Pretty or just a Pest?

In the Linda Vista Gardens in Abergavenny. I'd thought they were white bluebells, since they (blue variety) are all over the gardens, both Spanish (in profusion) and native, but given the bank in which they are growing was being swamped by three-cornered leek a few years back, which we spent countless hours trying to remove for the sowing of wild grasses and wild flowers, probably not. Three-cornered leek. Pretty. Every bit edible, if you can be bothered to clean the bulbs. And they produce miniscule bulbils, which you can't possibly remove, hence the resurgence.