It reportedly has radar reflectors and radio, for when it's on the surface.
At 3800 m+ underwater, it'd need to be a powerful beacon. Even most military sonar maxes out around half that.
You can buy one for a few hundred bucks, but based on everything I've read about this outfit so far, I'd be surprised if they even had that.
Additionally, if the problem was a power outage then the radio also might not work unless it had a separate power supply.
Emergency beacons cost a few hundred dollars and are designed for this purpose, not having one is pure negligence.
If they're on the bottom of the ocean then even if they're found a rescue is unlikely to happen in time.
In these situations you don’t do everything you can because it will change the outcome. You do everything you can so that someday soon you’ll be able to look at yourself in the mirror while you brush your teeth. So you can sleep at night.
I haven’t been in this bad of a situation, but I’ve been in plenty where people second guessed themselves or someone else for years even decades after. Everyone has to get to “enough” on their own terms or it festers.
So we are letting a bunch of people figure it out. If a miracle happens, awesome. But unless they’re all trance meditating down there and have Wim Hoff hypothermia training it’s not good.
Assuming it sunk, it'll be order of week before it's found. It'll be order of month before it's raised, if it can be. And then after analysis we might know why it sunk.
+60 hours after lost contact, while there are possibly still people alive inside the vehicle, seems premature and crass to be casting accusations for internet points.