I'm currently learning about the Kubota–Leopoldt $p$-adic $L$-function and I'm noticing that many people view the Kubota–Leopoldt $p$-adic $L$-function as a measure as opposed to a $p$-adic analytic function or as a power series.
My question is: What is the motivation behind viewing a $p$-adic $L$-function as a measures? It seems quite bizarre anda bit unnatural, at least from a beginner's perspective. Why is it natural to view $p$-adic $L$-functions as measures (as opposed to, say, as a $p$-adic analytic function or as a power series), and what is the advantage of viewing them as measures?