Most jobs are on-site.
The software industry, and things similar to it, like finance, certainly are suitable to work-from-home answers.
But construction, service trades (plumbing, electrical, roofing...), transportation, factory work, retail, restaurant work, farming, janitorial, and more, require people to show up for work at specific places.
How do you mandate that the work most people do, that can't be done from home, should be done from home. Yes the lock-down reduced carbon emissions. But those bounced right back, except for those few "tech" jobs that stayed remote.
Maybe require tech workers to stay home? Maybe the tech-worker shuttles could be electric? I don't think government is particularly good at nuanced rule-making. Let's solve the problem some other way.