Why individuals remain in subordinate situations (for example peripheral males at a lek or lowest tanking individual in a social group lie a wolf pack or lion pride) where they had limited access to important resources

By remaining in a social group even at the lowest rung an individual still maintains the benefits of being in a social group. See https://notes.utk.edu/bio/greenberg.nsf/4716d8bcc3a1c35685256d280059759b/2da1f68f0e36978185256d2e005fc3ed?OpenDocument for a great chart of the advantages of sociality that include feeding, reproductive and antipreditorial advantages. There also exists the possibility of increasing ones rank within a hierarchy by death or displacement of members. Basically as long as an individual has a greater chance of success in the group than on their own they will remain.