How is this different from voting by mail, then? e.g. basically everyone in Oregon votes by mail only.
WA also has vote by mail, but this kind of online voting is very different.
To vote by mail, you have to receive the ballot at your address, physically mark your choices, and then mail it back in. The potential for fraud or abuse of this system is fairly limited.
To vote with this WA online voting system, you need to know the name and the date of birth, that's it. Aside from illegality of voting fraud, the potential for abuse is just humongous, all you need is just a dataset of names and DOB.