It's not "all" they do. Fundamentals are a part of every drill, scenario, redzone, 2 minute, Special team, etc session they do in practice. What would be "non-fundamental" work for you? It doesn't matter if you have the biggest and baddest blitz scheme in the NFL or if you have a passing tree that spreads out over miles and miles. If you can't beat get lower than the guy across from you, beat a jam, run a crisp route, deliver the ball on time and accurately, or catch it when it gets there, it won't matter. everybody hates the term, but pad level, hand placement, ball placement, footwork etc are all essential on every single play. If all you do is walk thru the motions of an incredibly complex trick play, you won't ever have a chance to use it when it matters.