It's possible to phrase the value proposition to align with what you want to deliver.
You can phrase it as "I help teams deliver on time by making sure they don't get stuck." Or "I increase a team's velocity by preventing mistakes that stop work."
It's how you sell yourself and then, how you tell the story of what happened. Being able to tell a compelling story is important.
The issue is how do you provide the evidence for that. In other terms, how do you differentiate your effect from that of Homer Simpson's Bear Patrol and Lisa's tiger-repellant rock [0]?
It is really really hard to do that in a context where its not embedded in either work culture or appreciated by your lead.
It is easy enough to 'measure', a good lead would value how you benefit the team and enhance your co-workers productivity and seek to understand this part of your contribution. He or she could just ask your peers, it is not science.
If this does not apply to your situation at all, then leave because no amount of evidence will ever force your superiors to accept it, it will only antagonize them. You do need to make your case sometimes, but the level of proof should not be that high, you need some trust in order to function as an org even if it is exploited sometimes.
You can phrase it as "I help teams deliver on time by making sure they don't get stuck." Or "I increase a team's velocity by preventing mistakes that stop work."
It's how you sell yourself and then, how you tell the story of what happened. Being able to tell a compelling story is important.