Internet periodically drops every 30 - 10 minutes. EVERY DAY

Hi, I don't know if I am the only person dealing with this, but. My internet has been a pain in the [Edit: Language] lately. My internet will work for like 20 minutes, and then it will drop like no connection whatsoever. The modem will still have the white LED, like it is connected, but it isn't, and it's not just my laptop. It's every device in the house: TVs, phones, consoles, everything. Sometimes I do the speed test in the Xfinity app, and it says I have 78% or sometimes lower than what my plan is, which is 1,200 mb, and sometimes it will drop to 300 mb and 0 Mbps. I had 2 techs coming to my house, they checked connections and everything, changed my modem, and it still does the same thing. They said it falls out of their hands, Xfinity, read your forums, hear your customer base, YOU HAVE A PROBLEM ON A MAINLINE OR SERVER, OR WHATEVER, FIX IT. I am paying $80 a month for my internet to work LIKE I'M PAYING YOU GUYS TO DO SO. I have restarted my modem, checked every cable, done every procedure, chatted with your [Edit: Language] AI that can't do anything, chatted with countless online agents, and still, they can't even figure it out. Advance technical support contacted me, THEY CALL ME to talk to me about the problems I've been having. So please, I want an Xfinity support agent on this forum again to tell me Oh, let's do some procedure to fix your internet, I've DONE IT ALL.... ALL.