This is why random basement toilets used to be a thing. They weren't for pooping in the wide open of your basement. They were for easy access to clean plant roots out of your main from right where it came into your house.

Arguably they came with a bonus that if there was an issue with your main it flooded your basement instead of your upstairs because it was the lowest opening in your plumbing. I say arguably because if you don't go into your basement often you might not notice everything you are flushing is going onto your basement floor for a while.