And this is also a key argument when people try to justify oppressive laws by appealing to their own good nature: Protecting speech and protecting agaisnt the government isn't always - or even usually - against protecting against the present, but protecting against every future potential government, and especially protecting against those who might be attracted by tools of oppression created in the present to seek power.
I'm quite free-spoken most places, and usually feel more constrained by not wanting to be too controversial for potential employers etc. when writing under my own name.
But the shift in the UK recently has been particularly troubling to a degree I haven't experienced first-hand before, and while it makes me more cautious about how it will be interpreted now, you're right:
It's scarier to consider how these tools will be abused in the future.