Over-lubricating the chain causes foreign materials to accumulate in the drivetrain and makes it dirty.
Depending on the type of chain oil, it's even more so if you use oil with high viscosity or oil that attracts dust
In fact, rather than chain oil being bad, if you don't properly read the manual and don't clean it thoroughly enough
it will get worse. Whether it's wax or chain oil, excess of anything is not good.
