Compatible isn’t what you think. Phones want to boast about how fast they charge, but that’s not really good for your battery. You may have a phone that does adaptive charging. It’s pulling way less than it advertises so that it can prevent depleting your battery capacity over time.

If the plug fits, you’re fine. It will either charge slower, which helps protect your battery or it’s over what your phone requires, in which case your phone only pulls what it needs. You’ll be fine either way