1. Make any exclusivity agreements illegal. There should be zero ways for any non-wireless[1] company to block competition. 2. Strong push towards building communal fiber ("private trucks, public roads" analogy). 3. Need to do something about NIMBYs that block running the lines. Not sure what exactly, but surely there must be some legal ways. 4. Tax incentives for ISP startups are probably a necessity to help with the the initial costs.

Something like this, although I'm not sure this is a complete list - I'm not particularly aware about intricacies of starting an ISP in the US so there's probably something I'm missing.