"It's no secret that tech companies have not been hiring for sustainability and that sucks."

Does it suck? It means that someone got a job where they didn't really have to do that much and got paid anyway.

An alternative is where that job was never offered. And then we're complaining that there's no jobs.

Also, no, the solution is not to "just hire the perfect amount". Sure if we could just do anything perfectly everything is great, but how is that a reasonable demand.