Internet Is Only Reliable for FAANG Services

Steam, Discord, literally anything that isn't owned by a FAANG company struggles, if it ever manages to load at all. Even Xfinity's OWN WEBSITE is hard to reach, unless I want to give them money. And for services that require constant connection, like Steam, it drops CONSTANTLY.
I have found a "fix" for this, but it's not a fix. It's another service. A VPN.
It took me quite sometime to find this "fix," because any reasonable logic would expect a VPN to worsen a connection, not better it!
Do my speeds go down using this VPN? Yep. Does my latency go up? You bet! Is it still better than without? Absolutely, and that's infuriating.
I have spent A YEAR on and off trying to fix this problem. I have tried all of your guides. I have tried your bot. I have tried to get a person many, many, MANY TIMES, and have failed EVERY time. I have NEVER been able to speak to an actual person, except in store, where they have told me they have literally no power or access to anyone who could help.
I have racked my brain throughout this year to try and understand why in God's name a VPN would improve my internet service, short of this company violating Open Internet.
I finally got a plausible answer from someone that Xfinity may be trying to "optimize" my service by prioritizing certain sites. If that's the case, IT'S DOING THE OPPOSITE and I want it OFF.
BUT I CAN'T GET A PERSON. I can't get to a person to save my [Edited: Language] LIFE, and every other thread on this [Edited: Language] forum tells me to DM someone from a menu option that is either hidden or no longer exists.
I can't download games. I can't rely on Discord. I can't reach half the search results I get without waiting for minutes, if it ever succeeds at all.
If I'm not using a VPN, the only services that work properly are streaming services and social media. And I PAY FOR THE VPN, ON TOP OF XFINITY.
I quite literally have to pay more for the service I pay for to work as intended!
And I can't get anyone to help me.
Don't tell me to restart my router, I have done that dozens of times, sometimes on purpose, and sometimes because your stupid bot doesn't understand a word I'm saying and REFUSES to transfer me to a real [Edited: Language] person.
And don't you dare try to upsell me on some "gamer package." I pay for 1.2Gbps down, 35Mbps up, video games require no more than a few Mbps of data transfer at absolute MAX to operate. I don't need a "better" package.
And, by the way, I never get the speeds I pay for. I occasionally reach my top upload speed, but I've never seen my download speed above 800Mbps. The vast majority of the time, both are half what I pay for.

This is completely unacceptable. I know internet services are big, complicated, interconnected systems, but I have had other internet services throughout my life, and this feels either deliberate, or completely inept.
Neither of those is okay.