@olivias you can't get into trouble. It's not illegal but most white hat SEOs consider it the darker side of grey hat. It's certainly not a new thing either. Ever since authority was a thing in Google, there have been SEOs leveraging that fact. Back in the day it was a site called Ezine Articles (among others). Things have moved on since then.
And it's not just Reddit. There are tons of parasite websites you can use. Here's just a small selection that I've saved down during my time parasiting off Reddit:
- Medium
- Wordpress.com
- Quora
- Filmfreeway.com
- Weddingwire.com
- Pressbooks.pub
- Amazon S3 and Cloudfront
- Hackmd.io (sounds dodgy but it's not)
- Nas.io
- Groups.io
- Scribd.com
- Beehiiv.com (paid link)
- Github.com
... and many, many more.
When you start analysing the Google SERPs for high competition, review queries you'll find loads of 'em 😉