There are plenty of areas where fibre simply isn't available through no fault of the landlord, and the cost to provide service could be approaching the cost of a new house. It seems excessive to ban renting these properties out.
Banning new construction of individual homes in areas with no fibre likewise seems excessive.
However, requiring fibre for new subdivisions with more than n homes (and possible more than a certain density of properties) seems fairly reasonable, as does requiring landlords and developers to provide fibre connections where fibre is fairly trivially available.