The problem is that LS is incredibly easy to kite and the tanky meta heroes are either highly mobile (SB, Primal, ES), have great CC for kiting (Kunkka), or both. While Armelt/deso lifestealer is incredibly strong and good for damage dealing on tanky heroes, it’s very hard for him to keep on a single target.
Because of this mostly people play him as a siege weapon, where you either fight him or he continues to pressure the map/lane. IE the Midas/radiance or armlet/radiance build. But there are currently better picks to do that and offer more to their team (Spec, WK, Alch).
Mechanically, yes. You used be able to get to 5k+ with superb mechanics alone and people 2k-3k didn’t even know how to last hit properly. Now most 2k-3k players are at least decent at last hitting/denying and can cast their spells in fights.
Conceptually, no. People are still just as dumb as ever. The arguments I see from some averaged rank players and the things they do in game are really wild sometimes. The average player still has very poor conceptual understanding of the game and frequently makes glaring mistakes in basic concepts; how to lane, where to be on the map, where to fight, where to provide vision, what items to buy, power spikes, win conditions, etc.