It is the same in the US, and probably around the world. I do not see how it could be possible for more than 3 or 4 wireless networks to go around putting redundant towers up all around the country, especially big countries.

It's possible. Indonesia has 7 cellphone carriers with their own infrastructure, and I think 5 of them have national coverage. Used to be more but the number got reduced over time due to mergers and acquisition. I won't be surprised if there would be only 4 major carriers left soon if the largest ones continue acquiring smaller players, which is a bad news because cellular plans used to be very expensive when there were only 3 major carriers and these smaller players brought competition which drastically reduce prices of cellular plans.

It's possible... But then you go on to describe how it's ending due to consolidation ;)

You mandate that anyone who puts up a tower has to sell physical space and connectivity for base stations of competitors on those same towers at a fair price.

Charging to recoup the cost of the infrastructure = ok.

Charging more to force competitors out or to build their own, wholly redundant, towers = illegal.

How many base stations can you reasonably fit on a tower, how many redundant networks (even without redundant towers) can the market support? Let's say... 3 or 4?

What’s a “fair price”?

Like I wrote: covering the cost of establishing and maintaining the tower.

It's essentially a matter of declaring that the towers themselves, and the infrastructure that connect and power them, are not to be a profit maker for anyone. Can be made a condition during spectrum allocation, for example.

There's still plenty of other areas for providers to distinguish themselves.

And there's still an incentive to increase coverage. The only coverage increase incentive lost is the incentive of becoming a local monopoly. Good riddance, I say.

No private business is going to invest just to have its upside limited.

It's not its only upside.

They're already required to make sure the tower doesn't fall in someone's head. That cuts into profit. But they still do it.

Yes, the wonderful choice between RoBellUs or econo-RoBellUs sub-brand. Such overwhelming choice, I couldn't fathom having more options.

Don't forget the Chatr/Lucky/Public sub-econo-brands.