I want to leave.
But I'd like to download all questions I asked with their answers for further reference. Do you know a quick and easy way to achieve this?
Yes, there is a way! And there's no need to scrape web content, either, at least as long as you're only interested in your own posts.
Choose "Export my data"
Choose "Submit request"
You'll get an e-mail with a confirmation link. (The request form shows which e-mail address the confirmation request will be sent to.)
Once you confirm that the request is legitimate, a ZIP file of JSON files with your activity across the network will be prepared and made available for you to download. When it's ready for download, you get another e-mail with a link to a landing page where it can be downloaded.
In my case, the whole process took about 15 minutes.
You'll most likely want to start with the respective files named
If you're so inclined, once you have the post IDs for your answers and questions, you can download web pages with URLs like
https://<sitename>.stackexchange.com/a/<POSTID> (I just tried; that works with question post IDs as well) to get a rendered copy (including other peoples' answers) to keep alongside the raw JSON representation of your own content.
The JSON files also include at least recently deleted posts.
The only obvious thing that appears to be missing at a glance is activity on sites which have been shut down. That can probably be gathered from the last Creative Commons data dump, if you want to.