Developing a serious full size e-bike from scratch takes big money and needs to sell for big money, except the segment is way too niche for now, so really only the big five have the ability to eat those costs and live with poor returns, which they're not doing it because there's not much incentive for it. But, swapping out cordless drill batts for your kids to play in the backyard pretty safely? That's amazing for kids and parents and the category of "kids and parents" is massive. Even still, Stacyc isn't what it was with all the competition now. I'm sure their margins are a lot more boring these days, but they're able to overcome it by being in a segment large enough to support some competition.
Everything is getting better and heading in the right direction, like if you wanted to start your kids on something, it's kind of a no-brainer, it's going to be electric. Eventually, that will creep into more and more segments, but it's probably going to be 5-10 years before the 80-112cc bikes are equally as much a no-brainer. IMO, you just need to enjoy what's there for as long as you can keep it going. Anyone itching for electric shouldn't wait for it to be cheap and mainstream, because they'll probably be too old to enjoy it by then. Just buy it now knowing that these companies are going to fold and you'll need to get creative with parts, a hobby within a hobby.