Why are mastery tokens not obtainable in 3v3?
I've been playing only 3v3 for a while now and I just realized, upon hitting lv5 with a champ, that S(+/-) games didn't give me the mastery tokens to unlock lv6/lv7 mastery.
So I looked it up and the riot support site says that they're only obtainable from summoner's rift. Which got me baffled, because to me it doesn't really make any sense. ARAM or RGMs not giving it makes sense because their concept is completely different, whereas 3v3 is quite similar to 5v5.
The only issue I can see is game time, because 3v3 games are de facto a bit shorter so it may take less time to get the tokens in comparison to the rift; but that can easily be circumvented by implementing some mini tokens in 3v3; 2-3 of which could be exchanged into an actual token, if that's such a big issue.
Maybe there's something obvious I'm missing as to why there would be no tokens in 3v3, but to me it's pretty absurd having to play 5v5 exclusively for them, when 3v3 is just as serious or "legit".