Because channel URLs change every few hours to prevent piracy. The person who created the M3U link has a server that updates the URLs, but free public links are never updated. Paid illegal IPTV services charge for that dynamic updating bot.
Several services provide official M3U links, focusing on and content from around the world. These are much safer and more reliable than hunting for illegal streams: tata play iptv m3u playlist
Load your network M3U link to stream your subscription package on the go. Troubleshooting Common IPTV Issues Because channel URLs change every few hours to