If more users could vote, would they engage more? Testing 1 reputation voting on some sites

1-rep users can already cast downvotesvotes.

This is the message shown to all logged-in users who have less than 125 reputation on a given site:

Note this part of the message:

your feedback has been recorded

What about this data which you have been collecting for some ~13 years doesn't satisfy your needs?

Why can't that unsatisfied need be rectified by just changing the text of the modal rather than granting a dangerous privilege to people with zero experience on the site?

You could say something like

or something similar.

The impact of this proposed change is an unfair and untenable asymmetrical shift in power toward 1 rep users.

Currently, users of the site who have skin in the game (read: who answer or ask questions) can rest easy knowing that if someone wants to downvote them or upvote them, that someone will have at least also provided some kind of contribution. They've submitted some quality content at least somewhere on the network, either directly on that same site, or so much on another site that they've earned the association bonus on another site.

It's very easy to create an account, and if there's no requirement to learn how to use the site before that account can cast votes, you will see a huge increase in people casting votes for the wrong reasons, especially fraudulent ones. Voting rings will become a major issue for mod teams to deal with, more so than they already are (ask Stack Overflow mods if they want to increase the voting ring work they are doing by an order of magnitude).

As for removing the 1-rep cost for downvoting answers, I'm hesitant that will lead to more meaningful use. There's already no cost for downvoting questions, and those don't get downvoted nearly enough. I worry we'll just see people competitively downvoting other answers to questions they've posted their own answer to.