Welcome self-seeding plants
A large part of wildlife friendly garden maintenance is tweaking and curating nature rather than controlling it. I let plants self seed around my garden and love the excitement of seeing plants emerge and waiting until I can identify them before deciding what to pull out and what to leave. If it has a function or benefit to the soil, the wildlife or the look it gets left. If a cluster of seedlings are all too close together or somewhere I know they will get swamped I gently dig them up and replant in a better location.
Self-seeders in my garden:
Foxgloves
Poppies
Ammi majus
Calendula
Verbena bonariensis
Forget-me-nots
Erigeron karvinskianus