If other people using the internet is slowing down your connection, maybe it's time to finally ditch cable (if you're able to). Fiber is ideal, but even 5G fixed wireless is faster than cable, even during peak periods.

edit: in case anyone was curious, I get gigabit speeds from Verizon's 5G home internet, with no data cap, for $60/mo. Meanwhile Cox/Comcast charges that much for 20 freaking megabits, and you have a 1TB cap.