Just a comment about surrender and why its bad for dota. And Go Alliance, 7-0 G1 lan won't be a forgotten accomplishment for a long time.
Dota hero balance is more of a continuum based on time/farm. A quick and dirty illustration that is completely fabricated
Crystalmaiden - Jakiro ----------Juggernaut------Faceless / Antimage .... etc
And all the heroes fall somewhere on this line, some overlap, gold or networth moves positions around, but assuming equal levels and equal farm dota heroes can all be put on this line, in pub dota the hero compositions can be very fluid, and you can have amazing games with 10 heroes who peak past 15-20 minutes that are just hilarious, likewise, you can have a game with a team of 15 minute peaking heroes and push and a team with 5 late game carries that really peak at 25+ and the game can be very one sided. Often times dota really does come down to 1 team trying to end the game before this moment, and the other team trying to stall the game out. That's why we see so many varied strats and drafts in dota that actually function when the enemy team has the right lineup that's weak to what the goal is.
Items and their extremely powerful skills (orchid/sheep/bkb) all throw wrenches during the duration of any game. The items themselves even have counter design to each other, Evasion is countered by MKB and Sheep for example. Force staff is a viable counter to many skills.
What this means is that dota games are far more in doubt much of the time if the losing team plays them out still trying to win. Its also an etiquette to a point, the winning team gets to get a few extra kills breaking the base, you offer that fun to your opponent like they do to you. There is also that type of player who cannot stand a losing game or playing from behind and has such weak will that they are fucking annoying to play with, those players dictate surrender spam as well as harassment of teammates that they believe are the sole reason that the game is lost (its never them). Surrender should not be in the game, if your team agrees you can always smoke into the trees and mutually decide to not feed kills to encourage the other team to end the game
Comparatively to league, their balance is to have every ADC be as close to equal as possible, every top be close to equal, mid etc. Because the nature of items in league truly do two things, more damage, more defense. Holding on doesn't exactly mean much in league because you'll rarely gain enough traction to overcome the raw damage/mitigation that gold primarily gives. There is no Reverse polarity, black hole, ravage, AE 5 man stuns, etc in league, these single skills can win fights under large deficit. I don't think surrender is necessarily a bad thing in league, because without TP's, Smoke, camp stacking, jungle mechanics, and large teamfight ultimates there are very few ways to find or make space in league by comparison, you can't BKB TP, or many other things in dota that let you over extend against certain comps, and TP's really add another dimension to split push not to mention the heroes that can do it. In league the meta requires shen, or a hero to take teleport as the summoner skill to get a pseudo same result.
TLDR; Bit Long, but surrender would absolutely make the quality of dota games go down, in the high/vhigh bracket, people defend to the bitter end 99% of the time, and teams will push when they get ahead, the thrill of pond camping is not all that challenging most of the time compared to just starting a new game.