In our team one person was let-off last year. That person wasn't replaced and the work down was absorbed by the remaining team members. It got hectic.
Then there was another team that was working on X. Someone in the higher-up decided to move that team to project Y and our team was assigned X as an additional task. So that got added to our plates without any increase in resources. This added to the stress but after a few months we cut down on a lot of older tasks and were able to deal with this.
In the last 5 months, 2 employees have left the organization, both from our team. They still haven't been replaced. However, their work is being absorbed by the remaining team members.
Is it appropriate for managers to ask for more resources to replace the ones that resigned/were let-off?
If yes, then why doesn't anyone ever do it? I have more than a decade of experience in software. I've not seen a single instance of them replacing people who left the company + team. Is this normal?
Also, if yes, then is it appropriate for managers to call attention to the fact that "Tasks that cannot be completed until we get more resources for the team" to the higher management? If this is possible then I could escalate a couple of tasks as things that cannot be completed.