If I pay for grammarly, and it plagiarizes an existing work but represents it as an entirely new, independent work and I am unaware of the existing work that is being stolen, who is doing the stealing?
You can no more claim ignorance of where the github copilot code comes from than where the Amazon's low, low prices come from.
Whether you care is totally on you regardless of whether you pay ir not. You pay for product or service not moral absolution.