The problem is not that it spreads. It is that it then suffocates other plants that can't handle staying near it.

Of course having the ecological wasteland of lawns isn't good either. You want to create the conditions for a balance habitat to establish. Mint can be an obstacle to this and be detrimental to the biodiversity in your garden, if left unchecked.

Trading one invasive monoculture for another isn't really an upgrade, though you may get more utlity from mint. And your neighbors may set fire to your property.