Social keeps you visible. But it doesn't compound. A post does its job in a couple of days and then slides down the feed for good.
The stuff that compounds is content that lives on your own site.
It's a real explainer of a problem you solve. A piece of thinking only you could write, because it came out of years of doing the work.
That kind of thing keeps earning -- it ranks, it gets found, and now it gets read by the AI tools answering questions about your field.
If you've already gotten your expertise out of your head and onto your site, you're sitting on the raw material for all of it. The same foundation that makes your site clear is what you draw from to write the deeper pieces, the newsletters, the things you send a specific slice of your audience.
Posting and publishing are different jobs. If you're doing plenty of the first and none of the second, that's usually where the value is hiding.