I was reading a reddit thread where a new player was asking why X theme/mechanic in a recent set was not something he could build a competitive standard deck around. The responses in the thread was ENTIRELY set mechanics and themes are MEANT for limited not to build decks around. Is it a design problem that the player base feels set mechanics and themes are not meant for constructed 60 card formats? They did bring up how cards like Tenacious Underdog might have a set mechanic on them but them seeing play was because they were a strong card that happen to have it on them. Also it was brought up that Underdog could have the text just spelled out on the card and still function with out the "set mechanic" on it. Do set mechanics and themes matter outside of limited?

I’m not quite sure how to answer this. Clearly cards with mechanics are played in constructed formats, so yes, they matter. It’s harder to build solely around mechanics as you start getting into formats with larger deck sizes and singleton rules, but there are Standard decks where the main theme are based around using newer mechanics.Also, I should point out that high-level tournament constructed is a small portion of constructed play. Many Friday Night decks are built around mechanical themes. As you get more competitive, the very nature of it pushes you towards playing the strongest collection of cards which makes pure build-around theme decks lower in number.