Even IF I believed "the elites" wanted to depopulate the planet, the covid vaccine is a pretty stupid and implausable way to go about it. for one there is nothing in the science of how the vaccine works that indicates it has some kind of lethal effects. Sure it might have a greater incidence of side effects that previous vaccines, but thats a far cry from it being able to kill or sterilize most or all of the people who have taken it, and obviously we havent seen that despite like 3 billion or so people having taken it plus god knows how many boosters. There is also no scientically feasible way that the vaccine has some kind of a delayed reaction that would create that kind of a mass killing or sterilizing effect. If it was going to do either it would have done it by now. Global birth rates havent plummetted and people arent dropping dead from the vaccine in any sizeable numbers. If the vaccine kills people like decades after getting it then whats the fucking point, as those people could have already reproduced many times over by then, so you arent really reducing the population.

Now one conspiracy theory I could possibly believe is that covid itself was released in order to kill off the elderly and unhealthy, but if that was the case why are they pushing vaccines?

Occams razer my friend. The most likely explanations are the simplest ones. The simplest explanation is that covid was accidentally or intentionally released from a lab in Wuhan China, or was a virus mutation from some exotic food market in wuhan(which seems too coincidental to me)and most of what has been done since is people grasping at straws to put that genie back in the bottle and bring about a return to normalcy, with some overreaction to the situation and certainly no shortage of elites that are taking advantage of the situation to increase their wealth and power.