They actually have invested multiple times. Problem is the companies they give the money to just pocket it and don't update their infrastructure. Give this money to the local community or coop owned fiber operators. Stop giving money to these huge corps that don't need it and fund the small coop and community run fiber operators.

Fibre deployment is getting cheaper and easier. Both in terms of cost of materials and in the equipment and labour skills.

It's also much more secure from interference and disruption.

For populated areas, there's zero justification to rollout wireless over fibre lines. And most major cities already have fibre in most, or many, areas. And the thing with fibre is that the physical lines can be used to deploy faster speeds with upgraded endpoints.

Tech bros would have you think physical connections aren't a good choice anymore, because laying down fibre isn't sexy enough for that VC money.