Fast‑forward 20 years and battery technology has improved dramatically; EVs are affordable.
I think that that depends on one's finances. They are certainly more affordable than they were in the past. They also cost rather more than a comparable ICE vehicle.
It’s not just a lack of buyers
I think that lack of demand at present price points is very much the dominant factor. In order to transition soon
remember that it takes a long time for a car to "age out"
one would have to be selling a high proportion of BEVs and one would want the proportion sold to be rising. From last year:
EU car sales at 3-year low in August, EV sales plunge 44%
Sept 19 (Reuters) - New car sales in the European Union fell 18.3% in August to their lowest in three years, dragged down by double-digit losses in major markets Germany, France and Italy and sliding electric vehicle (EV) sales, auto industry body data showed on Thursday.

You can assess that there are negative externalities associated with ICE vehicles, maybe, and tax them further. Or subsidize EVs, if you feel that there are positive externalities associated with the transition. But at current prices, buyers are not purchasing EVs in the kind of numbers required for the industry to transition in the near future.


So, the US embargo was imposed in response to Cuban seizure of assets owned by US individuals and companies in Cuba at the time of the revolution, with the US requiring compensation as a precondition to end the embargo.
You've got inflation and interest on that too, so it does add up. But even so, Cuba has probably lost quite a bit more from the sanctions than it would have by just paying the US companies and individuals for the stuff it nationalized.
kagis
This is from 2005, so there have been another 20 years of inflation and interest on top of that, but it gives an idea as to the scale of what's involved (I just grabbed this source, even though it's older, because I wanted someone who had worked interest into the claims; a lot of sources only adjust for inflation):
https://ascecubadatabase.org/asce_proceedings/taxation-of-cuban-confiscated-assets-after-property-claims-settlements-issues-for-taxpayers-and-the-u-s-government/
The US has a pretty strong incentive to keep the sanctions in place until compensation is paid, above-and-beyond the Cuban situation, because it doesn't want countries around the world to say "oh, let's just seize this asset owned by some American; free stuff". If someone's thinking about that, the US can point at Cuba and credibly say "you might take it, but the cost will exceed your benefit".