I’ve dealt with this at least twice on behalf of clients. In both cases, another provider entering the market was the only thing that made a difference. By that point, they’d already burned all the good will they had in the area, so maybe they would have fixed things with competition, but I wouldn’t know, my clients got on the waitlist to jump ship the absolute nanosecond they hear about it.
The op showed starlink as a comparison. It was one of several 100Mbit options. Comcast is the only service above the 100Mbit level at 1200Mbit advertised .
100Mbit seems fine? I obviously don't have the full picture for what the OP is doing with their line on a day-to-day basis, but, saying that you're entirely out of options when there is an option that is just slower is a little odd
(I do get that Starlink is also quite expensive if it is not your only serious choice)
Given that they have multi-minute outages multiple times per day and they're still not switching to one of the 100mbps options, I think it's a safe assumption that they really do need that speed more than the reliability
I'm a heavy user myself and would be perfectly pleased with a symmetric 100/100 connection, but would even rather make due with 20/20 if that meant no regular outages, so I would agree with you but OP's needs seem specific
Starlink service is blacked out if you're within 20 miles of a radiotelescope that uses nearby bands as starlink. Maybe that's considered an edge case, but I can promise you Comcast has a lot of neglected infrastructure in those areas. I have receipts to prove that service dropouts are from outside the demarc but I had to waste a lot of time getting a tech to come out and say "looks fine to me".