OP, you provided a balanced and fair perspective of what you found disappointing on your cruise that was not what you had experienced on prior cruises.
Food: disappointing
Internet: disappointing
COVID protocols: perplexing
Service: Inconsistent / misunderstood
All fair opinions to express here.
However, by doing so you will encounter those that agree with you and those that will not.
My 2 cents that others have mentioned: if this cruise on this line disappointed you so greatly to consider taking your business elsewhere, that is exactly what you should do. Only then will you find out if another line will live up to your expectations. Read about those other lines to see what others are saying about those things you found disappointing here (food, internet, COVID protocols, service) to gain perspective.
If you so choose, Happy Sailing!