It certainly is in high-density neolithic+ societies, where most threats are intra-group.

It may have been less so in the preceding 99% of human existence.

The Alpha will still defend you against lions or raiders if you're banging his skinny Beta brother or cousin. Against one of his homies, maybe not so much, but the balance of threats will have varied over time and space. The Beta may have been "good enough" most of the time.