I've seen this happen to many managers at FAANG. You're promised 10 people for a project next year, you get 4. So you cut, manage, optimize, engineer, and hustle to get something done and working. Management above you sees this as relative success, and validates that they were right not to give you more people. Disillusionment sets in, the team quits or transfers, you get bad reviews.
The next year, you're fired or transferred, and the new guy comes in, he gets 10 people, saves the day and gets high praise. He gets good reviews and maybe a promotion. You look back with resentment. The problem wouldn't have been there if they had given you the resources you said you need. If you had 10 people, you also could have saved the day.
This is the sickness of large organizations and non-technical management. I have rarely seen organizations not run by owners spend the $1 on prevention today, they almost always elect for the $10 for a fix later.
If you need 10 people to do a job, and you get 4, the job should fail. Your systems should be going down. Don't sabotage, but upper management needs to see, not hear about, failure. Update deliverable timelines form 6 months to 18 months or just cancel new projects all together, change your SLA's from 99.9% to 90%. Change your ticket response times from 30 minutes to 12 hours or best effort business hours.
You'll either get the resources, get attention for reprioritization, or learn that your job isn't a real priority.