I know of two ways to make people care about accessibility.
The carrot. And the stick.
The carrot is inspiration. You can show people how accessible design makes products better for everyone. You frame accessibility as good design that benefits all users, not just a compliance checkbox. And you hope that people genuinely get excited about it.
Then you have the stick. Lawsuits. Regulations. The threat of getting sued or failing an audit. It's not pretty, but sometimes fear of consequences is what finally gets accessibility on the roadmap.
I'd prefer the carrot, but sometimes the stick is the only thing that works.