this i.e. outdoor equipment such as true offroad Jeeps & RVs, along with military and maybe company vans, are the 3 real areas where I expect gas/diesel to remain as part of serial hybrids.  I think for all but company vans, that series hybrids with MULTIPLE smaller eng-gens makes great sense. At this time, things like company vans, like for plumbers, where they transport lots of tools and supplies, but then sit for hours or even days, should remain as plain old ICE for a long time, until EVs become truely cheaper just to own. At this time, Tesla EVs are cheaper to own due to better economic efficieny (i.e. electricity is much cheaper per kwh), and teslas now have the best resale value of any cars going. Shortly, as major car makers switch to EVs, they will be forced to do decent EVs and not this junk they currently do (bolt, i3, leaf, etc are pretty much $20-25K junk that costs ~30-40K)