Having seen that often newcomers (included myself when I started here) are too quick in accepting an answer, and having also seen that the reminder to wait at least 24 hours to allow a wider batch of potential answerers goes practically unnoticed, wouldn't it be better to make the capability of accepting an answer within the first 24 hours a privilege one hearns at, let's say, 1000 reputation?
In this way the benefits of waiting would become evident to any poster.
I'll add my opinion to apaul34208's that this doesn't solve any real problem, and particularly not one that justifies such a fairly drastic change. Code change complexity aside, moving a feature that has so far been available to everyone to be available only at a relatively high reputation level is a pretty drastic change, and it would leave newcomers with potentially no way to indicate that they are happy with an answer. (They wouldn't be able to vote up, offer a bounty on or accept an answer. All that would be left would be to leave a comment, but that's not what comments are for.)
It is up to the OP when, whether, and which answer to accept. For a current, somewhat extreme, example, do consider Does WannaCry infect Linux? on the Information Security SE, where the accepted answer is currently at -20 with only four upvotes, but the highest-voted answer is currently at +52 with only one downvote.
We can point out to the OP the consequences of accepting an answer early, including that it reduces the chances of them getting even better answers to their question, but if the OP feels a given answer answers their question to their satisfaction, they have every right to accept an (the) answer.
There have been proposals to make accepted answers float based solely on votes, and perhaps acceptance functioning as a tie-breaker, the way acceptance works with self-answers. Other, similar proposals have been made that are slightly different, but still accomplish the same goal of not putting so much emphasis on acceptance status. Compare e.g. Let's move some negatively scored answers from the top spot on Meta Stack Exchange.
And of course, "in this way the benefits of waiting would become evident to any poster"? You have 10k now, so you can see all the low-quality posts that pose as "answers" which are really just comments, posted as answers because commenting is not available to new users. Not to mention all the people who regularly complain about commenting not being available to new users. I think we can reasonably conclude based on experience that it doesn't work the way you posit that it does.
As much as I still feel that we should be careful about accepting answers early, limiting access to basic features of the site (which are even integral to how the site is supposed to work) is something that should also be done very carefully. Better, then, to simply point out to the OP the benefits of not accepting an answer too soon.
Terrible idea, what you would end up with is a bunch of questions with no accepted answer. You can't coerce the OP into doing things, he/she is here for their own needs and possibly just transient in any case.
Honestly the problem you're trying to solve seems negligible... As in it doesn't happen often enough to warrant a systemic change.
I know it's irritating, but it's not a major problem. People can still modify their accepted answer long after the requested 24 hours, so what problem does this solve? Truly I hate being "that guy", but sometimes I have to be... Accepted answers are fairly meaningless to anyone who's been kicking around on the network for a while, maybe I've lost perspective... Does the the check mark still matter to new-ish users? it's 15 rep, but that's a drop in the bucket toward anything meaningful.
