You write about loyalty with a lot of warmth here. What comes through most clearly is that feeling of being carried by another person through all the awkward, unstable, painful parts of growing up and beyond. That gives the poem its heart.
I especially like the shift from insecurity into steadiness. The early doubt makes the later bond feel earned. And lines like “we showed up for each other” and “we always had each other” keep it grounded in something real, not overly dressed-up sentiment.
Simple, sincere, and quietly moving. It reads like gratitude that has actually lived through something.