Should I quit after my manager blocked my internal transfer because I'm "too valuable" to replace?

I spent the last three years busting my ass at a mid-sized tech company. I automated half our team's reporting pipeline, trained four new hires, and consistently hit top performance tier every single quarter. I thought I was building the perfect foundation to move into product management.

last month an internal senior PM role opened up. The hiring director specifically reached out and asked me to apply. I crushed all three rounds of interviews. The hiring team was ready to make an official offer with a thirty percent pay bump.

Then my current department manager BLOCKED the transfer behind closed doors.

He told HR that my current team is "understaffed" and that losing my daily output right now would cause operational disruption. HR agreed with him. They canceled the offer and told me I have to stay in my current operational role for at least another twelve months before re-applying.

The hiring director apologized to me privately and said his hands were tied.

So basically, if I had been mediocre at my job, they would of let me leave without a second thought. But because I carry the team's workload, I am literally being held hostage by my own manager. Now I have to quit a company I actually enjoy just to get a promotion. Why does corporate reward incompetence and punish actual work?