Thanks! I'm having a dumb day and I took some more photos and Google Lens now suggests fringed willowherb. I blinked and now nearly all empty spaces in my garden have been taken over by these. I think fireweed are quite pretty and I this that bees and butterflies like them too? Would you suggest leaving them?
They are both Epilobium, but fireweed is much larger and showier. They are both rather aggressive to be left in the garden unless you are going to regularly pull out the vegetative spread and really you have to remove the flowers before they go to seed or it pops up everywhere. Fine in a weedy area. Bees like it. It already grows all over the place.