>This would aim to fix that.

i.e Local Roaming. The problem is there is no way to ensure QoS over the network. You will need additional functions to ensure the network is best every time you switch.

>What do people here think of that? Would it help?

I am assuming you are talking about US MNOs or Carriers. And I am often lost and dont understand how anything in US works. It seems there are decent options, like Mint [1] which offer very decent 5G price plan, especially considering the wages across US. $30 for Unlimited or $25 for 20GB is very respectable.

So I am not exactly what the proposal would help, or trying to fix or improve.

Edit: I will add more context. If it is about better coverage and more site being built. Then this is actually a property ( surprise surprise ), regulation and market issues. No Technology is going to save you if the market, regulation or the people / culture does not allow you to install a 5G radio because they are scared.

[1] https://www.mintmobile.com/plans/