Modems Keep Dying

HI, I've had THREE modems die since February.  I had a Surfboard, so I got a new (and supported) Netgear.  That Netgear lasted till last week.  I just purchased another Netgear (again supported) and had it activated last Saturday PM.  This morning the Internet was DEAD.  I went to Best Buy and got another (again supported) Netgear Router.  Can ANYONE tell me why the modems are dying?  The Surfboard Modem was top of the line a year and a half ago.  I used to get 220+mbps on the Surfboard AND Netgear.  Last Saturday PM (5-2-2020) it started out at 120 mbps, and that was fine.  This morning it was not working after several re-boots.  Now it's working this afternoon, but albiet 12 to 20 mbps.  Again, can anyone help me with this??  Thank you in advance for any help.