Joke used to be that folks would carry a CB radio for safety. Get in trouble and they send a tow truck. VHF has a bit better range and is marine oriented, but you're still limited by the capabilities and resources of the folks within range.
EPIRBs use a satellite relay to the folks best able to direct the response of available resources.
My son got a helicopter ride after the fishing boat he was working sank and they hit the EPIRB. Rescue was compounded by two problems. First, the VHF antenna on the EPIRB had broken, and the heli couldn't home on the VHF. Second, the weather was foggy so the heli was relying on FLIR (heat seeking), but the crew was wearing gumby suits hence little heat emission. Things came to a safe conclusion after they popped a flare. As I recall, time in water was less than 3 hours. He's still got the rescue T-shirt and I've still got my son. I like EPIRBs.