There are still old telephone co-ops from the early days of the telephone in the US. The one I'm thinking of is extremely rural (population density is < 2 people per square mile), with a median county household income under $25K. They put in fiber to the home years ago, and 1GBit symmetric is well under $100 a month. (They have cheaper plans too.)
Similarly, some places have started using companies like this:
You pay them to build out a local fiber network. You just pay the line installation, and then the community owns the network. The minimum project size is about 100 houses because that leads to a $100/month per house bill from the incumbent network's $10,000/month fiber uplink.
Concretely, imagine there was a subsidy for any area that doesn't have 1GBit symmetric for under $100 a month. Starting in the poorest communities, use the ACP money to establish a local co-op (per community, creating jobs) that charges 1.1x the cost of the fiber uplink per month, and saves 10% for network expansion / maintenance.
The ACP burned through $14.2B since 2021. It costs about $10K to run fiber to a house (it's almost all labor, so in urban areas you have short runs with high cost of living for the workers, and in rural areas you have long unobstructed runs with low cost of living).
They could have wired 1.4M low income houses for fiber with that money, and the co-ops could then charge the houses well under $100 per month for connectivity.