Don't jump to conclusions. Fiber Optic cable is just recently hitting a lot of neighborhoods. In fact mine was installed by Wire3 and I expect Spectrum to buy them out pretty soon.
Go for a trial run and see how it performs for you. Don't expect miracles, it won't make old equipment new again.
Look for WiFi6 on your phone or tablet, and you'll be doing OK.
The good thing about Spectrum is that they don't normally require a contract, so you can quit anytime.
The second thing is that most of those bad reviews you refer to are likely about coax internet by Spectrum, now that is outdated tech.
Fiber is the way to go.
I had Spectrum coax internet for years....If rain was in the forecast the internet would go down, If the wind was above 15mph the internet would go down. If we actually got a storm....It would be out for days. AT&T ran fiber through the neighborhood 2 years ago & don't believe I've had an outage!