I think it reasonable to consider your salary as coming from something you have. Your human capital is an asset.
You can’t trade it as freely as other assets. You can only partially sell it’s future value streams (e.g. consumer loan, special clauses in work contracts). And it has its own risks that may or may not have a high correlation to the local or global stock market. As a side note: The stock market is notoriously not highly correlated to the present economy.
There are other assets that don’t behave like a stock market ETF. Annuities, Cat Bonds, Swiss farm land, your home, your company, social capital, etc. We still can consider their contributions and risks. Modeling them as such enables thinking and talking about it. And that should inform our investment strategy.
The most clear application of this is probably life cycle investment.