My idea was that you could type an artifact name into the filter and all the planets with that artifact will show up. I mean u see an artifact on a planet then forget which planet holds that artifact, and yeah there may be others with that artifact on it, but you want that specific planet to show up rather than searching through hundreds of planets and wasting a lot of time.

No thanks. Some like to hide warehouses on meh planets.
This idea would just hurt that strategy.

If it worked on just planets you own then I guess it would be nice but ehh i have mixed feelings on it.
I've had an annoying time combing old planets for the old limited size 1 artifact 1 structures for fancier new planets. But at the same time my patience in doing so yielded me a small gain. So doing the boring annoying stuff gives you a slight advantage over others which is good. Rewards those who try just a little harder.

I have to agree with all of Tree's points.

Plus, I know several GL players (including myself) who keep notes on enemy occ planets to invade in the future and extract useful artifacts. People spend a lot of time searching for storage planets and inactive treasure troves, there's no need to dumb the game down so much that you can just type in what you want and voila!