Someone by the name of Aryeh wrote an excellent, insightful comment on the previous post which requires discussion: I think you miss a lot of subtleties here. Yes, the final authorities on all issues are contemporary posekim. This is how it's supposed to be: each community must follow its own leaders in its own generation. This is what we learn from Parshas Shofetim, where the Torah says "ובאת אל הכהנים הלוים ואל השפט אשר יהיה בימים ההם". As Rashi explains ad loc., the Torah says "in those days" to teach us that we must follow the leaders in our generation even if they're lesser than previous generations.