Any game where the last survivor wins are based on the idea to get involved as little as possible early on (unless extremely high rewards are given along the way).
Regarding your point about the last survivor winning, that's partially true, but partially not. What you're essentially describing is a proto-version of the non-aggression pact we saw develop in the last weeks of Halite 2016 (and which was indeed largely successful). However, even there, it wasn't quite so simple; competition winner mzotkiew had an excellent write-up of his strategy at https://github.com/mzotkiew/HaliteBot/blob/master/writeup.pd.... Halite-II makes non-aggression even more difficult due to the lack of discretization found in Halite I.
source: conceived of and co-developed Halite.