California Broadband Definition Undermined by AT&T

Probably because the morass of red tape and bureaucracy in the way of building a competitor has made such an endeavor difficult to accomplish and that this was the case from the very beginning of net infrastructure. Recall that Ma Bell was made national carrier in exchange for not competing against smaller carriers. When the government starts picking winners and losers rather than letting companies duke it out in the market place, you get long term consequences like incumbent carriers that are economically inclined to only do marginally better than its competitors, if anything at all.

And that's not considering the extreme bureaucratization and state instituted monopoly clauses that prevent profitable investment in infrastructure even from titans like Google.

Because installing fiber wires to every residence is not profitable when the local coaxial cable company can give everyone low quality 500Mbps down / 3Mbps up connections for $45 per month. It is why you usually only see fiber in brand new developments where there is no additional cost to bury it while everything is already excavated for all the other utilities, or in older neighborhoods with overhead wires where it is cheaper to install.

If you are in a relatively modern area with buried utilities, there is almost no chance a business will be willing to take the loss on running all the new fiber underground.

It has to be a taxpayer funded effort operation like a utility, otherwise it will make no business sense.