Voyager 1 & 2 is one of my favourite human science achievements, not even so much from technology standpoint, as it's relatively simple compared to what we have now (although that's one of the charms), but just the fact that it's so far away, it still more or less works long after the scheduled mission end time, we can communicate with it and despite all the modern technology progress, it would take decades to catch up. Absolutely amazing and inspiring!

They are dangerous and reckless. They were also done in the name of humanity, but without humanity’s consent.

I despise the naive scientists who did them as much as those who brought the damocletian sword of nuclear weapons on us.

I assume you are against them due to the silent forest hypothesis? Better not announce ourselves, because anything out there might not be friendly to us?
The vast space of everything seems to me that any intelligent life eventually discovers physics to get out of this dimension. Dune space feudalism is unlikely

The dark forest hypothesis assumes that it's easy to travel between stars, so interstellar conquests are possible. But it doesn't seem to be the case.

There are no material goods that can justify the material and energetic expense of any interstellar travel. You'd be far better off just using a particle accelerator to forge any chemical element and then assemble them into molecules using nano-replicators.

The best you can do is to send information, possibly with the help of gravitational lensing.

Sci-fi mode on: given that the potential galactic civilization is going to be information-based, who's to say the Earth is not already under attack? An interstellar fleet of large invasion ships with soldiers is not feasible, but a small drone with an AI that connects to terrestrial networks and steers the civilization towards collapse is possible. I'd start investigating if TikTok algorithm developers got some nudges from a weirdly knowledgeable source.