In the last 7 years, we have identified 3 objects which definitely originate from outside the solar system. Prior to that, none. So we either failed to identify them, or?
Curiouser and curiouser.
Prior to that we didn't have the telescopes in orbit looking for them.
‘You can observe a lot, just by watching” - Yogi Berra
We didn’t even know that our galaxy was one of billions until 100 years ago. Up until around 100 years ago most of us thought our local group of galaxies was the universe. We couldn’t discern planets orbiting distant stars until very recently.
Our observation platforms and methods are getting better, so we are seeing things we missed before. That’s all there is to it, it’s not some great conspiracy.
It is because of recent efforts to find asteroids which could impact Earth. Now that the Vera Rubin telescope is up and running that effort has been kicked up a notch. It has the capability to photograph the entire sky in detail in less than a week.

The top two images are from the telescopes which are being used to find asteroids. These are the same telescopes which discovered 3i-Atlas. The bottom picture is from the Vera Rubin telescope.
Coming thru the Oort cloud this will kick loose hundreds of comets — into the inner system.
Lots of dinosaurs died this way.