A smaller battery with a range of 40-100 miles would allow most people to do their daily driving strictly on battery. Beyond that, a gas/diesel generator should kick in for range extension (or for towing).
This is because smaller batteries take a long time to charge (usually AC only), and small capacity means they need to be charged frequently (often daily).
BEVs can have batteries 10x larger, which also allows them to charge at a 10x faster rate. The larger battery can last a whole week on a single charge. Quick infrequent charging makes them tolerable even without having a charger at home.
BEVs also don't cycle whole batteries that much, because driving 30 miles daily will use 10% of the battery, not 100%.
But it has a range extender. That transforms it from essentially a dedicated grocery-getter to a daily driver that can commute all over Socal. Barely over 2 gallons of gas will give you an extra 70mi (at about 65mph)
Granted, it's more a technology demonstrator than a blueprint for an affordable mass-market EV, but it's a huge step in the right direction if you ask me. Much more similar to what the average person in a city needs in a car than, say, the 600hp model 3 I was driving around for awhile.
Realistically, I think it makes a lot more sense to have a dedicated BEV with whatever range you feel appropriate, and a dedicated gas vehicle (if needed) for road trips and longer jaunts. For the vast majority of people, renting a vehicle makes a lot more sense for those occasions.
Generally, I think the populous seems to highly overvalue the ability to take a road trip on a moments notice and undervalue the ease of just being able to rent a vehicle.
Would you believe that on three separate occasions I turned up to collect my (reserved and paid for) vehicle on a Friday, ready to go on a road trip, and they simply didn't have a vehicle for me?