Perhaps it be accurate to say the given our current knowledge about the parameters there's not currently a Fermi paradox, but if we gained more information about the parameters then a Fermi paradox could arise in the future.
IMHO the Fermi paradox has one flawed assumption: that interstellar travel for the purposes of colonization would be possible and desirable. If this is not the case then there is no paradox, everybody is in their solar system happily doing whatever it is they do all day.
Is it even worth it?
As to self replicating probes that's freaking dangerous. Get something wrong and the universe becomes a very hostile place.
PS: In terms of cost consider the % of humanity's GDP spent on SETI projects. Now consider those at least have the possibility of some benefit in your lifetime. Extra Solar probes are unlikely to get much in the way of resource investment from most civilizations.
That means sending people out.
We would be sending people on one-way trips, for better or worse. You'd likely never hear from them again.
As to just sending out Bracewells to say "Hi", why? Once again, the return on a response is very long and not guaranteed. And without a response, what's the point?
The point was that the galaxy should be filled with whomever figured out how to colonize distant star systems, even if it takes a 10,000 years for a colony world to get to the point where it can send out the next wave of interstellar colonizers, that's a drop in the bucket for a galaxy that is billions of years old.
Which requires the probe to return information.
> because it's interesting to learn about others
Which requires the probe to return information.
> to trade technology, philosophy, science, and media
All of which, and say it with me, requires the probe to return information.
At the speed of light, that return will take four years from the nearest star.
> If just one alien civilization sent out a Bracewell probe a century but started back when the dinosaurs were around they could have launched a million probes by now.
And if 'if' were a skiff, we'd all take a boat ride.
What is the benefit of launching one such probe? Especially knowing that your next launch is in 100 years. Voyager, after about 40 years, is just barely out of our solar system.
Voyager is broadcasting at 19 watts and we're barely getting that signal here. And it takes 16 hours.
So instead of contemplating what would happen if hypothetical civilizations with hypothetical technology would do for hypothetical reasons, think about what we can and would do right now with our technology.
"People" can be made pretty small if all you're sending is DNA and robots to grow them.