I'd argue that twenty years ago, weed legalization was still a pipe dream. It was only consistent advocacy and activism that has slowly bent legalization policies to where we are today. There's a non-zero chance that we can change the way we do things, because car dependency has only been the policy for seventy years or so, and we only arrived here by changing what was. We can do it again. To the point about trillions of dollars: it costs about that much to replace our roads every twenty years or so (that's about the lifespan for a residential road), and it's getting more expensive because of shit like Amazon using the fuck out of our interstates and shortening up their lifespans (heavier vehicles increase road damage quadratically). All these infrastructure bills are so insanely expensive with seemingly so little to show for it because we haven't been doing the required maintenance on our roads, and we're still not seeing the full bill. So, to be completely straight with you about it, it costs as much as you're describing just to keep what we have, because car infrastructure doesn't last very long/hold up very well compared to other transport modes.

As for your annoying vegan point: maybe, maybe not, I guess we'll see if it does turn people off. I do think it furthers the conversation, though, because this is more or less the arc of how marijuana advocacy progressed. This is a little like saying that protestors should only protest if it will inconvenience nobody at all; if you protest and nobody notices, it's not really a protest, it's digging a hole and screaming into it.

Anyway, you seem to be upset, so maybe it's best to just let this conversation die off. Have a good day, stranger.