I'm out in the country in Colorado. I have a small local ISP. I can get 10Gb if I want it. I have 100Mb because that's all I need. Honestly, for most people, I really don't know what you'd do with 25Gb. Even 10Gb is tough for alot of home users. The equipment is out there and not even that expensive, but its also not something most people own. Most people who own that sort of stuff are either home labbers or tech enthusiasts. And even if most people did, they would rarely use it to its full potential. For most people 2.5Gb is far more practical. Oddly enough it can be harder and more expensive to get your hands on than 10Gb because it's just starting to really penetrate the consumer market, where 10Gb was common in datacenters for a long time, so used equipment is quite reasonable.
The biggest issue with ISPs in the US is that you have legacy players entrenched in a market and unwilling to spend the money to do upgrades. The main reason I have what I have is because a local company saw an opportunity to go into a space others were failing badly at and used a state grant to help fund the buildout. Soon, I may have a second option because my electric co-op is working on their own build. Since they answer to their members and not the stock market, now that fiber is cheap, they can build this stuff widely. We need more of all that.
To make you even more jealous, the 100Mbps I pay for tests as that, both up and down. For $48/month, no billing shenanigans. I had 1Gbps for a bit and it was testing near gigabit ethernet's theoretical maximum, both up and down. Fiber to the rack is kind of awesome. Oh and when I call for tech support, I get somebody local. I've actually gotten one of the owners before. And they do a yearly Halloween party/customer appreciation day. Talking with one of the owners, it's like he practically expects that people are going to be downloading those 4k Linux isos.
You'd probably like what I had before - awful DSL. I was near the maximum limit for DSL. The technician said the line could do 15Mbps. I usually ended up around 12. And I was the lucky one. Some of my neighbors were like 1.5. So glad to dump Centurylink.