I feel Heavy vehicles will come thick and fast once viable market propositions are easily accessible. For these buses, if they're at least 2 years away, they'll ramp up fairly quickly beyond that.
Thats the main thing holding all EV's back. It needs to be viable for you and me and a business to buy one.
What exactly is a "viable market proposition" for you then? China has 421,000 electric buses already. I've been doing a 110km daily commute for the last 18 months in a car that's four years obsolete, which cost me roughly as much as my colleagues spend on their ICE vehicles.
If your new car budget is $2000 - and believe me, I've been there - then no, an EV is not for you. But neither is any vehicle that's not old enough to vote & drink on its own.