What if this is the opportunity for a shift in transport modes and requirements.
We're seeing onshoring at an unprecedented level now, and therefore a reduction in imports. This means less coming into the cargo terminals, and more produced "locally". If this continues, then the hub and spoke model for much distribution will change.
Secondly, could a shift to more efficient bulk transport occur? What if it was a shift to double stacked containers on the rail network to move bulk and volume? Still would be hub and spoke, but move the bigger distances with a kilometre long train.
Once that's moved to the hub, yes it may need decanting to a semi trailer, but that might be to the next node in the network. From there it's into the final 50mile range and that might be an EV 12 tonner or so, and that could get you into the city as needed to do the drops.
Coming back to the arguments about emission standards, yes, American pickups do have to meet standards but because of how they (and full size Suburbans etc) are classed, they don't IIRC have to meet car standards - they pass as a truck. Car standards are stricter generally, but the growth in demand for the pickups that don't meet that mean that the car fleet average for the Big 3 is staying fairly low... But if the pickups and Suburban-esque 4x4s were included as a representative range of sales to private users it would sky rocket. This I think is ultimately what they are trying to tackle with thesr sorts of proposals. Unfortunately, others get caught up in the same mess.
Solutions? I'd advocate some very big tax advantages for new vehicles, and scale those through over 5 years or so. The problem is that the lifespan on a truck chassis is pretty decent, so this will take time to trickle through. What you're trying to do is increase a supply of modern, compliant vehicles that then flow down to the small operators over time. The small guys don't have to outlay for the newest equipment, but there is a clear advantage in upgrading in time. This is very much what happened in the UK with a move to CO2 based road tax, at first it was too expensive for low income earners to get a car that had the lower tax, but over about a 6 year period it become a viable option, and now there's lots to choose from that are affordable and cheap to tax.