Screenshot, Youtube download, whatever, have a copy of your stuff and back it up.
related: reddit actually has a fairly robust "archivist" community and the site's search function is usually "good enough" for people to find answers to many questions without having to be a registered/logged in user (because someone else almost assuredly had a similar question that was asked & answered in the past).
As an IT person I'd say you need to remember that backups can also get lost or corrupted.
If you want to be sure, heed the advice given to students writing essays - have a backup in 3 different places.
That could be
1. Your PC hard drive.
2. A USB stick
3. in some Cloud storage.
Whatever you do, bear in mind that tech keeps changing. Your backups will also need updating to keep up, if you save them long enough.
@dnsprincess This is one of the most important things to remember.
I always copy my stuff on my external harddrive, have it twice on my laptop, take screenshots and get it on my phone, just in case!
Already lost some things (a year of photography) and don't ever want it to happen again