I am not entering this debate, but I do want to correct what appear to be some misunderstandings you may have about PLBs.

You are correct that PLBs have proprietary batteries. Some PLBs do have user exchangeable batteries. In either case, it's really irrelevant. The batteries in PLBs are lithium based with a 10+ year functional life. They typically have a 5-year service interval in keeping with the conservative nature of the industry, though in most cases I expect by the time you need to replace the battery, you'll probably just purchase a cheaper, smaller, lighter PLB. PLBs also include a self test feature and the latest PLBs check that the batteries have not been discharged beyond a set limit that ensure they will still meet their transmission specs at the end of battery life.

Your comments regarding reliability are simply unsupported by fact. Compared to any other signaling device, 406 MHz distress beacons, including PLBs, are simply the most reliable means of declaring distress and summoning help, far more so than a cell phone or sat phone which have much more significant operating limitations. In many scenarios where a cell or sat phone may not work, a PLB will get a signal out and provide distress alerting and location.