Perhaps this is an idealistic and naive world view but internet connectivity _should_ transcend governments and be something that no one has control over and no one can shut down.
They don't though. From a technical view point, they have the same "off switch" that every country has: boots on the ground, guns and trust that they'll use them. They didn't switch the internet off, they ordered the service providers to switch it off. Every country on earth can do that with the service providers that are running physical infrastructure in the country, it's harder for satellite internet.
There's absolutely no reason why the US, Germany or Switzerland couldn't do the same. They probably won't any time soon, but they can: all it takes is a few phone calls and the service providers' belief that they mean it.
"National security" is the blanket answer to all those questions.
VPNs, TOR, steganography and obfuscation are some of the best tools against tyranny.
Remember, this is the country where one of the charges they brought against Aung San Su Kyi during the Feb coup was importing analog two-way radios. And more broadly, people are regularly arrested and imprisoned or sometimes executed for mere possession of radio equipment.
That would literally require a man in the middle attack; the jammer should be kept between the antenna and the satellite, or very close to that position. I mean, it should be in the air.
"as well as locate them"
Possible, but not easy. A satellite dish can be buried, hidden under a camouflaging roof etc It's not like earth antennas that need the space around them free for pointing them; all they need is to see their satellite which is in the sky. One can dig a hole in the ground, put the dish down there pointed to the satellite, then when not in use park their truck above it, and good luck to the government helicopter passing above to track it. And btw, there are ways to build antennas that don't appear as such; they may offer worse performance but they do work, and satellite reflectors can be built that way too.
Or you can shoot down your enemy's satellites and screw up the orbit so he can't launch any more.
Pretty sure Myanmar can't do that.
Seriously, though, if the tech needs to be actively camouflaged and there's death penalty only for its possession, there's no way many people will use it. So it will be useless to inform and organize people, it will be useless to broadcast what's really happening inside.
Not doable unless either you are in between the dish and the satellite, or have an extremely powerful transmitter with its directional antenna pointed to the dish, where all that power is needed to cope with the fact that the maximum sensitivity of the dish is towards the satellite, not your jammer. Which also means that they need one jammer and its antenna for every dish they want to silence. That would not scale well.
(With all the risks that comes with operating + defending a detectable RF emitter from the ground in a hostile environment)
If you want to work to prevent this, keep enough technology and know-how on hand that you could do this on short notice, even if's as simple flinging 5mb/s on a cantana a mile away.
Governments could block sales of the customer equipment, but once they're in it would be almost impossible to locate and confiscate them all.
They could order termination of service (based on coordinates or serial numbers), but there's no way for them to physically control that if the company refuses to do so.
adding on this: I'd agree with the notion that it is weird that people fetishize the internet as some anarchic free entity when on a material level it is owned in big parts by private interest.