Looking for an explanation of security risks when allowing insecure connection from a client

Hey all. I’ve been trying to find a reasonable explanation online and haven’t made progress. Here’s the gist: my parents have a ten year old Samsung tv. It won’t connect to my server unless insecure connections are allowed in the client settings. From what I gather, it’s Samsung being a lazy bum.

What are the realistic risks here? Is it mainly a risk if someone is on their LAN already? Or are there other risks? How would a bad actor exploit this?

My parents are old and training them on a new streaming device is a non-starter, unfortunately.