I don’t know if this is an unpopular opinion or not, but I’ll expose it regardless.

I don’t think that the less relatability of the PT characters is due to the way the characters are written, but simply to the acting. For example, I live in Italy, and the Italian dubbing is much more dynamic than the original acting. It’s less flat, and as a result the characters seem more human. In fact, I have never had any problem empathizing with the PT characters, precisely because the Italian dubbing is more dynamic and human, and therefore it conveys different sensations than the original acting, to the point that many of the lines that are considered cringe in the English-speaking world sound perfectly natural in the Italian dubbing.

To prove my point, here there are some scenes from The Phantom Menace, Attack of the Clones and Revenge of the Sith in my native language:

Padmé confronting Anakin on Mustafar (ROTS)
https://youtu.be/jer_qlWqmHI

“You were the Chosen One!” (ROTS)
https://youtu.be/sES8yVAjQuY

Anakin meeting Padmé for the first time (TPM)
https://youtu.be/6nUGTq2mPT4

Anakin meeting Padmé again (AOTC)
https://youtu.be/2hv2uzd3Mng

The elevator scene (AOTC)
https://youtu.be/CLtl4HRzqMU

Anakin and Padmé talking on the grass (AOTC)
https://youtu.be/E_PMWp9hT1M

As you can see, the acting is much more dynamic here than in the original version.

I can sort of understand why George Lucas chose a flatter, less emphatic type of acting, but it affected the films in the long run.