On Twitter, Google’s Gary Illyes confirmed that over-optimizing your web pages can have a negative impact on your website rankings:
@bubba_ji That is totally a thing, but I can't think of a better name for it. It is literally optimizing so much that eventually it starts hurting
— Gary Illyes ᕕ( ᐛ )ᕗ (@methode) 24. Mai 2017
Use the Top 10 Optimizer in SEOprofiler to find out if your pages are over-optimized: