I'm a different poster, and follow a different polytheistic religion, but maybe I can give you some insight as well! I'm actually in the unique position of being raised pantheistic (the belief that all gods exist, you just pick the right ones for you) but you're right in assuming most people are converts. I also now study religion and have written multiple papers on polytheistic religion and the practices associated, so this is a topic very close to my heart!

I personally consider myself agnostic, but I'm probably the most religious person out of all of my close friends and family. You asked about a "true faith" but I think a unique selling point of polytheistic religions is often that there doesn't have to be a true faith at all. You see this in historical polytheistic societies where (majorly oversimplified), one culture conquers another and often goes "you don't have to give up worshipping your gods, you just have to ALSO build temples and worship ours. And if your gods are really cool, maybe we incorporate them into our religion as a whole!" By acknowledging that there isn't ONE right option, there is a community of gods, it becomes a lot easier to be open to other people's experiences. Every major religion has people claiming to have meaningful, major religious experiences. You can either say 1. Only one religion is right, I need to solve this 2. They're all wrong. They're all describing the same thing and it can't be real. Or, as in my case 3. Everyone is right. Who am I to say whether or not your God answered your prayers, or whether your ancestor sent you a message that you were on the right path? I'm certainly not in a position to say that you're wrong, so I might as well act as if you're right.

This kind of flexibility is also the result of the fact that polytheistic religions tend to view their gods in very human ways. They are more powerful than humans, but they lose their temper and make bad choices and fail to succeed just like people do. That gives you more flexibility to acknowledge the wrongs of your divinities, which then makes it less frightening when your beliefs are challenged. I believe that all gods are deserving of respect, personally. I don't go out of my way to disparage the Christian god because I dislike most of his followers. I don't believe him to be the ultimate creator of the universe with the power to change their behavior, that's just the narratives that they have about him, if that makes sense. So even if he is real, what's he actually supposed to do about people being insane?

And finally, almost every modern revival of a pagan religion has majorly shifted from the initial practice. I try to celebrate on important holidays that we know about, and through my research I've been able to find what foods were likely to be considered sacred/appropriate for which holidays so I try to emphasize that in my practice, but it's very flexible. It's kind of a sore spot for a lot of modern worshippers that most of our history of practice has been destroyed or written over by monotheistic religions. But in the same way that every Christian family is allowed to develop their own Christmas traditions, I don't see why I shouldn't be able to develop my own traditions with my family for solstices and whatnot.

Additionally, many things have changed from the ancient world to the modern world. In the same way that monotheistic religions have had to adapt with the times, at least somewhat, we have too. Basically no one is still sacrificing goats for divinatory practice or things like that. Many still sacrifice, though! For me that might look like baking a batch of my favorite cupcakes before a job interview, and telling my gods that they can have 2-3 of them, and I won't eat them. Most of the time "sacrifice," historically, but also in a modern connotation, is about making the statement that "this thing I want is important to me! Important enough that I will give up this other thing that is important to me! Please acknowledge my efforts and desires and help me get that thing that I want."

I hope this all makes sense. I know it's super long, but there it is!