It could be argued that work like this actually helps make people's data more secure.

Granted, owners of the affected hardware might not like it, but this sheds light on issues that are actually present in the hardware. Who's to say that "law authority" or some criminal organization didn't do any work on this without intention to publish their results?

If people have sensitive data and were counting the T2 chip to keep it secure, now they know there are limitations to this security model. They can now weigh the pros and cons and, if applicable, set up an alternative that will be more secure. This could also push Apple to provide better security in upcoming products.

I'm glad they released their jailbreak, because otherwise, those exploits would be sold and traded on the black market or collected and used by malicious groups, and we would be none the wiser. We'd walk around believing our machines are secure, and act like it, while that clearly isn't the truth.

The same work allows users to have control over the hardware they own as well.

So only the NSA should be able to do this and then also keep it a secret?

Imagine if their "evil twins" working in the dark or for the NSA, KGB or Red Army, have cracked this but not tweeted about it. Now the Apple security is just as broken but you don't know about it. Is your data more or less secure?

Law enforcement has been going apeshit about legally forcing Apple to build in hardware backdoors to their products. If this jailbreak didn't exist, they'd be putting a gun to Apple's head and demanding decryption tools for all iPhones.

Furthermore, the entire point of a jailbreak is to regain root access to your own device - Apple provides no way for a user to do so, which I find at least somewhat irksome. The way it currently stands, all iOS devices ship with Apple having total control over the device, and a jailbreak lets you claw back control by force if you so choose.

The T2 isn’t used in the iPhone or iOS devices.

What makes you think state actors with inifinite budgets didn't do what this one guy is doing?

Everything he exposes will be fixed and improved. If anything he's helping make Apple devices more secure.

It's work which is enabling freedom, something that people are unfortunately giving up far too much of these days...

I think that over-simplifies the idea too much. "Freedom" on its own isn't a constant positive. We don't give people the "freedom" to murder each other or modify their cars in whatever ways they want. In fact, some people choose Apple because it doesn't provide them the freedom to do anything they want which includes breaking their devices in ways that they don't know. Having that freedom isn't necessarily a net positive for some people.

Go back and do your homework.

Showing security problems is the opposite of making Technology less secure. Maybe ask Apple why they think it's a good idea to have closed source special chip at all.