Tired of Reddit's recent shenanigans and want to cause them a little bit of pain? Well now, my friends... why not add "request all of the things" to your Reddit exodus?
The link to the appropriate page is here:
https://www.reddit.com/policies/privacy-policy#policy-h2-2
So, why might you want to request a copy of your data?
First, the collection they (eventually) send to you will contain your entire post / comment history, allowing you to (in theory) use that collection to remove all of your posts versus the last 1000 or so of each. There's no guarantee that Reddit won't restore those posts, of course, but at least you tried!
Second, you can scour the data for personally identifiable information (PII.) Your local laws may entitle you to removal of PII, so if you're inclined to purge the Reddit record of information that can identify your OMG real self... that dataset may help.
Third, you'll have a copy of your Reddit history. All those epic ideas will be in your hands, not theirs, safe to share elsewhere as you please. While you may not have the right to revoke the license you gave Reddit by posting there, you can most assuredly re-use your post as you please, wherever else you please.
Fourth, and lastly? If everyone submits data requests, Reddit's team has to spend the time (and money) to pull your data. it might be a small thing, but inundating Reddit with tens of thousands of data requests that they're legally obligated to provide is both wise (for you) and at least a little bit costly (for them.)
Addendum: If you want to make things a little harder (at risk of them not responding) you can use their privacy email versus their form. That way, someone likely has to verify that X request is tied to Y account.
If you're persistent, sites usually end up complying to make you go away. I've had to fight other sites (Instagram) for removal of my photos copied to spam profiles. It takes a bit of back and firth but they generally end up complying. Might help to cc their legal department if they exceed the deadline.