• Quality and subtitles would still be an issue.
• You potentially have slower speed compared to official streaming services and definitely slower than your self hosted content.
• You potentially run risk of losing access to the content if the site gets shut down.
• good luck explaining how a pirate streaming service url is totally legit whereas your plex/jellyfin app is not.
• some of those streaming services you still need to pay for, or seed content for other people so they’re not “free free” for good quality ones.
• if you’re buying a usb device loaded with access to one of those sites then that usb device may have malware and no im not just making that up, it has legit happened. There was another more recent story I’m failing to find.

Anyway, i think it’s a bad idea. It’s not for me. Good luck if that’s what you want to do. But for the love of your parents don’t use a modded streaming stick unless you want them to get targeted by fraud/ identity theft. No amount of free content is worth that risk.