I don't think that's an adequate response.

I vote with a mail in ballot. My signature is checked by a human being (I know as a family member was audited when their signature differed from historical).

Couldn't web-based replace paper-based mail-in ballots?

With an on-file signature that generates a "voting token" that could be mailed to me for goodness sake, I don't see why mailing in a piece of paper with ink on it is a necessary step.

Some countries do use electronic voting (using state PKI based systems) that in many sense is similar to mail-in ballots.

I can recognize two problems with these.

a) vote buying, b) vote stealing.

Risk for vote buying is similar for both methods but electronic voting has in my opinion higher vote stealing risk as it is easier to implement on large scale.

I think both methods are suspicious and I am not in favour of them, but as usage of mail-in voting is not widespread, it does not involve too big risk.

Contrary electronic voting may become very popular and problems will be magnified.