Trains are great and they're definitely underutilized in the modern world, but the thing they excel at is getting stuff from point A to point B (like a warehouse), not spreading it around across thousands of different destinations.

Building a light railway to each and every walmart, target, 7eleven, etc. it's just not practical in any way:

My city, for example, has a relatively extensive tram system. You can get around most of the city by it and there's quite a few stores that are right next to tracks, so, theoretically, something like that could be used to deliver goods within a city.

However, it's, both, way louder than cars and trucks (I used to live right next to a railway) and every time a tram or its powerline break, the entire line stops. You can't, exactly, drive around a broken tram when you're on rail.

Rail can't realistically be connected to everyone's house. You always need a solution for that final mile.

For smaller stuff, a (cargo) bike is a perfect solution.

For heavier stuff, like a mobile work place or a 40ft steel beam, you will always need something else. Right now the best option is a (small, electric) van or truck. For that you will need at least some roads. You can prevent them from being accessible to anything but professionals who absolutely need access. But you will still need a limited amount of them.

Perfect is the enemy of good. Being a zealot about this, is self-defeating and won't convince enough people.