My presumption is that batteries have been expensive enough up until now that it's been most sensible to target upmarket without sacrificing specs vs ICE. My expectation is as prices continue to fall cheaper and cheaper cars will become commercially viable.

Cheap EVs suffer the most from the drawbacks that make electric kind of suck (smaller batteries reduce range, more sensitive to heating costs, etc). Once you can shove a 60kwh pack in a cheap car, most of those drawbacks go away.