&gt; You can call methods with explicit self too.<p>Point is &quot;signatures are different&quot;. You can&#x27;t use this function in place where you need signature without &amp;self.<p>&gt; You&#x27;re not supposed to<p>It makes life of web-servers harder.<p>&gt; Could you expand on this point?<p>To parse JSON with nested objects you need to declare a lot of structures. When APIs are difficult, people even use code generators.<p>&gt; It&#x27;s idiomatic<p>It&#x27;s not an argument. What work should work. Idiomatic or not - another question.