You do not have to speak with the insurance adjuster. It is the adjuster’s job to get claims resolved. However, it’s also the adjuster’s job to not pay out too much for claims. The insurance company makes a profit by maximizing the premiums they take in and minimizing the amount they pay out. It’s just the way it works. The adjuster is the first line of defense. You do not have to speak with them.
At some point, however, information about the nature of your damages suffered will need to come to light and be communicated. It’s best to have an attorney makes these communications for you. That way, you will not accidentally surrender your rights or say things you should not.