Internet is extremely slow after multiple efforts from xfinity

I have had horrible service and inconsistent internet for quite a while. Xfinity sent out a tech that told me I had an inadequate modem and needed another xfinity approved modem. The recommended modem cost over 200.00. After purchasing and setting up I had average service for a while then it got worse again. Now it is so bad that my wife can’t even send emails or use her peleton.

To add detail I have the arris white modem capable of 2.63 gbps. Also, the Google mesh network with 7 pods throughout the house. It was an expensive solution with the hope that I could bypass the [Edit: Inflammatory] WiFi and network supplied by xfinity hardware.