Artifact Transmuter, I kinda don't understand its use

I got back into Genshin for the new artifact set and haven't played in months. Noticed the red bubble notification in my inv tab. Realized they added something for like a guaranteed artifact and the tutorial was vague.

I fed the thing with my spare artifacts and got an elixir and tried to get a goblet but realized I didn't have enough elixir. Only to find out I could only make 1 elixir for said amount of time.

Now I feel like I wasted those 4 artifacts I could've used to power up a better artifact. Is there a way to get more elixir? Do people even use this?

After using it for the 1st time, I feel like its not worth it. I feel like I can farm the artifact in the same amount of time of getting 4 elixirs.