Plug-Ins allow renters to participate in the energy ecosystem. Also, people who live in apartments, not independent homes. This is probably more than two-thirds of the people on the planet.

Plug-ins increase energy literary. People will learn to love their energy (IKEA effect).

Germans and other European countries buying them will create demand, and products will become cheaper and incredibly reliable.

There are zero labor costs, no need of electricians or permits. Instant energy/energystorage on tap.

Billions of poor people will just buy plug-in products or panels (like Pakistan), and the creative explosion of ideas of a billion people will create many interesting products for a range of uses.

Small correction: They are actually incredible reliable by today!:-)