Your power system is really interesting! The idea of a familiar being a fragment of one's soul has a lot of potentials and raises a lot of interesting questions. As a reader, I would probably wonder about the sentience of the familiar. Is it more like an extra limb that you have complete control over, or is it more like a pet? How intelligent is it? This is something you might want to flesh out.
Also, worldbuilding-wise, I wonder a bit about what you mean by "due to progress in society people have become somewhat shallow spiritually which has lessened spiritual attunement worldwide". Generally, societies progress out of necessity. For example, we didn't really stop relying on whale oil until we started to run out of it. Usually things only change if a) the old way breaks and are forced to mass-convert to another system or b) someone invents something that works better for cheaper, and people slowly start converting. B) can only happen if society progresses enough that we can focus on investing in the invention of new fuel instead of basic necessities like proper infrastructure and food. And B) will be slower, because people who are used to the old way aren't going to suddenly throw it away just because theirs a new option, even if it's better. People tend to prefer tradition and even if they like change, it can be costly. The reason I'm bringing this up is because I'm wondering why people would shift away from familiars when familiars are already working. That doesn't mean they aren't going to, it's completely plausible that they would, but what would cause them to do so? What progress was made and why was it made, when familiars already work so well? Or do familiars not work as well as modern tools, and this progress is better? If that is the case, what reason do we have for learning about the familiars? Basically, I think you should expand a bit more on why familiars are dying out and what their impact on the world is, and why the characters might choose to use the familiars over whatever modern tech they have.
I also was wondering how you would do things like bond with your familiar, or how soul energy is measured. It's fine if the latter one isn't ever really fleshed out tbh, lots of stories are vague about power level, but it's something to consider.
The need for soul energy is a great restriction to put in, and it could lead to a lot of interesting situations if the characters run out of soul energy. What happens to the familiar if they get low? Will it also be affected? (this question kind of assumes the familiar is sentient)
Keep in mind that I'm super biased and my response is less of a critique and more of stuff I think readers might want to learn about or stuff you could flesh out to make interesting situations. Also, I don't know anything about the themes and characters in your story, so some of the things I said might already have an answer or not need an answer.
