If you are in the US and can afford a $3000–5000 veterinary bill, then you don’t need it. $3000–5000 is easy to spend at a specialist… surgery for a torn ligament in the knee of a dog can start at $4000, with a likelihood that the other knee will tear within one year. Do you have $8–10,000 sitting around for this surgery? I sure don’t. A cat with a urinary blockage can cost you $2000-3000 the first week, with more costs in followup care and special diets.
Don’t expect pet insurance to cover wellness care, or even 100% of illnesses and injuries. It is to help with the bulk of the cost of major problems that you cannot reasonably plan for.