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/sES8yVAjQuYAnakin meeting Padmé for the first time (TPM)
https://youtu.be/6nUGTq2mPT4Anakin meeting Padmé again (AOTC)
https://youtu.be/2hv2uzd3MngThe elevator scene (AOTC)
https://youtu.be/CLtl4HRzqMUAnakin and Padmé talking on the grass (AOTC)
https://youtu.be/E_PMWp9hT1MAs 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.
I do not think that is an unpopular opinion, but it certainly an interesting one.
Personally, I think it is similar in other language dubs too. The non-English versions that I have seen usually have more energy and flow to them, in delivery of the lines, and also in conversation with their counterparts in scenes. It flows more naturally than the original English language delivery. Almost like a fan editor may choose or prefer when trying to bring more emotion, energy, more intensity to some PT scenes.
Although I do not think it was something George chose to for the PT (‘flatter, less emphatic type of acting’), I think it was part of his lack of direction or care to attention for dialogue heavy scenes. I think it is something he or his highly skilled editing team in the OT fixed in post/in the edit. In the Prequels that editing team (and ‘the heart’ or emotion from Marcia) was not there, and it could not be fixed, with many scenes appearing stilted, stiff or just plain flat. Maybe more “Do it again one more time. But faster, more intense” from George on set was needed?
It would be interesting exercise to see English voice actors (or impersonators), maybe even the original PT actors redubbing the PT now, but with more emotion, flow and energy, to see if that improves the PT films overall, and how much by.