Wood siding vs hardy board vs plywood

Has anyone used just basic 3/8" smooth wood siding for their exterior walls?! The guy at the lumber yard suggested it because it's already weather treated and just needs paint...my dad suggests hardy board because it's "awesome" and will last a long time. (I veto because my 110 lb self can't pick it up!!!). A lot of people use ply wood and weather treat the heck out of it and/or cover it in fiberglass or metal or some other sheeted siding. Would love to hear thoughts on easiest most cost efficient options. My current pick is 2x framing with 3/8" wood siding on exterior and 1/8" ply or luan on interior unless someone on here talks me out of that plan.
. New to this whole thing...have my design, working out the build plan details!
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