The thing is, "teamfights" don't happen from the start either in this. There's 2 lanes, and people are split between the 2lanes. They insist multiple times in the various matches they've shown that you want people in both lanes to maximize xp gains, then you want people to go down the mine(on that map) while you keep people up to still leech the xp there. It isn't 100% teamfight. Mostly you have a few minutes at the start where you're doing NOTHING because you don't need to last hit, so you're trying to find a way to kill someone, which, surprise, you also do in a normal moba. Jungler ganks/bot lane pressure in LoL and trilanes/roamers/gank runes open a lot of small fights early game(and in dota with the availability of TP scrolls they can quickly degenerate into full blown 5vs5 depending on the teams).
Now obviously you wouldn't need to last hit even if you could since there's no items, so no need for gold. What that means however is that you basically cannot win a lane unless you're playing a retard or towers are ignorable(not too sure on that) since all you have to do to not lose your lane is stand in xp range and not die. It makes all the early game pointless as fuck as far as they've shown. Whoever wins the early game gets exactly no advantage whatsoever, and the game is decided in the last 5minutes or so, depending on who plays the last couple of teamfights best/has the best hero composition, and everything before is just there as a massive filler. You cannot win or lose lanes and winning the secondary objectives early on doesn't really bring any serious advantage since the heroes aren't able to properly capitalize on the golems/canons due to being too low.
As for depth/variety, removing items removes a very large amount of variety. There is no arguing this. LoL often has 2 or more potential builds for a given champion(AP, AD, hybrid, support, tank, one of these) while Dota items simply can change a hero into something entirely different since most of them give unique gamechanging abilities(blinking, invisibility, pushing units, magic immunity, physical immunity, illusions, spellblock, cooldowns reset etc).
I'm still very interested in this game and I think there's potential for a hearthstone type of success, but in no way this is going to come close to dota or lol in terms of competitiveness/depth, similar to how HS isn't close to MTG. And dota2 is getting player made custom game modes soon enough.