You are your own best marketer. If a great product is out in the world, but no one is told about it, did it exist? It's not just having the product, it's having great product marketing to go with it.
Make your impact visible or it doesn't exist
Leadership → Influence Without Authority
If you built something within the organization that you're proud of but no one knows about it, then that's more difficult to have as your stamp of approval for what you are able to accomplish there. But if you did something that cross-functional leaders were speaking to, that your team all sings the praises of, then that is something that you can put a feather in the cap.
I wouldn't want to do that because it's self-promotion. But instead, what if I called it educating about all the great work your team has been doing? Helping people see why your team should get more resources, you have to actually share what you do.
If you think your self-review is self-promotion, you're just not going to do a great job at it. What if I called it educating your manager about all the great work your team has been doing?
Getting promoted is way harder if you're not good in telling stories and rallying the team behind the shared goal and all these kind of things, and you usually achieve this through good storytelling techniques... I would consider it a bit of a career staller if you don't get to a decent level of storytelling and to a decent level of public speaking.
Writing externally and getting momentum externally was a better way to influence internally what was happening at Shopify. There's so much noise that it's hard to tell a 200 person PM org to stop and pay attention to an idea.