Last time I was given one to ride for a month Rad bikes were basically aliexpress bikes with very crude Bafang electronic assistance which is lightyears behind what Shimano, Bosh, Yamaha or Brose provide.

You don't have to be state of the art to be a bike company. Part of their appeal for me is that they aren't 'state of the art'. They use commodity parts which means that I think they'll be repairable for a lot longer, and they also cost less than half of any of the other brands you mention (just for context, the cheapest Giant e-bike powered by Yamaha costs more than double what a Rad costs, and has a smaller battery).

Kia makes cheap cars using less than cutting edge technology, but that doesn't mean that they are any less of a car company than Mercedes.

Sure, they cater to the low end. But, their designs aren't off the shelf (or aliexpress), they have a network of showrooms and shops, and most importantly there primary business is the selling of bicycles.