I personally don't trust any residential fiber claiming it is dedicated. They may carve out your bandwidth (how they were required to do in DSL world) & back into the the math to not over-subscribe the nearest fiber node but there is no SLA (service level agreement) so claiming it is
dedicated is just a sales pitch. Until you enter Enterprise business fiber with money backed 99.999% up time... fiber and coax aren't that different. Many residental fiber connections are a copper handoff behind your house (not all) or hit copper 66 blocks leaving your neighborhood. You likey pass these utility boxes often around your home & don't recognize them (copper not glass inside):

All the ATT fiber in my neighborhood eventually hits those.
Coax is fine for 99% of home users. I work from home often and have constant VPN, Cloud apps, VOIP, & streaming IPTV going over my coax connection with no issues.
Now I get nice speeds but at some point, higher bandwidth the vast majority of the time is better than a lower guaranteed carved out bandwidth.
I vote for the overall higher speeds but I've never used Charter or Cox. For example, with Comcast I pay for 200 mbps down, I regularly get 237 mbps down. They could guarantee me that I'll never get below 175 mbps which is the low end I get. I'll take that over a guaranteed 50 mbps from ATT fiber any day. Now enter the business world with SLAs & hundreds in businesses on 1 node, different story. I recommend fiber there.
Also, no ISP is advertising in bytes. It is a common end user mispronounced word. Carrier speeds are measured in bits (m
bps). Storage (such as HDD or flash) is measured in bytes. The "B" is shown as a capital letter such as 1TB HDD. I even hear Telecom savvy people who work at carriers say this wrong often. If you hear a carrier rep saying "bytes" then they are 99% likely just mistaken. I seriously doubt they are doing the math and dividing by 8.