Artist role in game optimisation and pipeline for mobile


Hey all, I was wondering if any artists out there have any experience with game art optimisation and if so what are the best pipelines/options to take.

Also what is the responsibility of the artist when it comes to optimisation of art assets.: Apart from the usual (image size and and export compression) Is the artist in charge of compression types within unity, assets bundles and the measuring performance on devices?
I have had a interesting time with my own experience where at times it feels like purely guess work at times with the lack of documentation.

I’d love to hear how others approach game optimisation.