> multiple NAS and distributed them geographically and used Syncthing to keep them updated
As some one working in storage, please do not get tons of NAS they are pain to manage eventually. Example: linus-tech-tips could not do it properly.
If you use youtube-dl how large is one video? Lets say 2 GB. I presume, every week you create have 2 videos? Then 4GB per week.
Google gives you $20 for 100 GB. Every year create a new account - like - company name.2022 dump everything there. Hire an clerk to make sure the credit card is payed every year.
That way you do not lose all videos at a time.
Heck you can even create free Google drive account every few months and segment them.