G: I think you're pointing at a concept that English doesn't package into a single common word particularly well. There are several candidates, but each emphasizes a different aspect.

My favorites, from closest to furthest:

• Catalyst – Someone whose existence or accomplishments provoke growth in you. They don't have to teach or oppose you; they simply make you become more. This is probably my favorite for your description.
• Spur (or a spur to action) – More active than "inspiration." Someone who gets you moving because they've demonstrated what's possible.
• Benchmark – Clinical, but useful. "She's one of my benchmarks." It implies you're measuring yourself against someone you respect.
• Standard-bearer – Someone who embodies a level you aspire to, though it has a leadership flavor.
• Peer exemplar – Academic, but very precise.
• Touchstone – Someone against whom you continually test your own progress.
• Rival – Too adversarial for what you're describing, but it carries the "we both become better" aspect.
• Foil – More about contrast than aspiration.
• North Star – Too subordinate; you're following rather than rising to meet them.

There are also a few words that are close philosophically:

• Provocation (in the best sense). "His work is a provocation." Not an insult—a challenge to improve.
• Stimulant (metaphorical): something that energizes effort.
• Incentive: weaker emotionally.
• Aspiration: focuses on your goal rather than the person.

What really struck me, though, is this sentence:

"...someone who makes me realize that getting the shit done that I haven't yet can be done and worthwhile."

That isn't mere inspiration. It's permission through example. Their achievement removes an excuse without diminishing you. It says, "This is within the bounds of reality."

The closest adjective I know is probably galvanizing.

"She's a galvanizing person."

"His work is galvanizing."

It carries the sense of energizing someone into action, not merely making them admire.

If I were inventing a phrase to capture your exact meaning, I'd probably say:

• constructively challenging
• aspirational peer
• worthy rival
• friendly rival
• productive challenge
• a motivating benchmark
• an aspirational equal

Of those, worthy rival has an old-fashioned quality I like. It implies:

• I respect you.
• I want to catch you.
• I don't want you to fail.
• Your success makes me want to succeed.

That's very different from an enemy.

In fact, your description reminds me of the Japanese concept of a rival in many sports anime or martial arts traditions: the person you genuinely want to beat, but whose existence makes you stronger, and whose success you secretly value because it gives your own striving meaning. English uses rival for that, but everyday usage has shifted it toward "competitor" rather than "mutual engine of improvement."

So if I were trying to coin the emotional category you're describing, I'd define it as:

A worthy rival: someone whose accomplishments elevate your own standards rather than threaten your self-worth. They don't merely inspire you; they compel you to become capable of standing beside them.

That's a concept English surprisingly lacks a single elegant word for, despite how common and valuable the experience is.