To add to what others are saying, you should consider the framing of your question. Progress isn't all-or-nothing. There will still be situations where a truck, van, or car is the best tool for the job, and electrifying them will take time, or require advances in technology. We would still benefit from expanding public transportation and decreasing the need to use a personal vehicle for everyday tasks.

Eventually, though, yes, it would be good to replace diesel trucks with trains where possible, and electrify the ones we can't, when we can.

Edison Trucks out of Canada is betting on diesel-electric hybrids. They're starting with logging trucks but if they succeed (or if someone copies their ideas) I expect they'd expand into long haul.

It still burns fuel for the generator, but with regen braking, charge-depleting during acceleration, an engine tuned for a narrow power band, start-stop for clean idle, and the ability to charge from the grid overnight before short hauls, it can't possibly pollute more than straight diesel.

Like for example, my gasoline car can do about 30 MPG highway and worse in the city. Pure ICE drivetrains suck balls in the city. A 10-year-old Prius on its original battery can do 50 highway and 50 city. I expect hybrids can squeeze some efficiency out of diesel the same way.

If you're actually serious, you could replace many of them with something like this: https://www.freightliner.com/trucks/ecascadia/