I agree with this.
From a cashflow perspective a lot of "remote first" companies just use cost of living adjustments because, well, it's cheaper and employees are happy to oblige. This the dirty little secret.
Here's the reality - the profitability of a tech company is directly related to the amount of total cost of running the business (duh) and human resources is typically one of the largest (usually at least 40% of the overall revenue on avg in my experience). If the same engineer is working remotely from NY versus Kansas City, their output doesn't change as a result of where they live, so profitability only changes if the company renegotiates their package (their revenue contribution stays constant, so only cost changes the profitability measure).
The only reason the salary is higher in NYC to begin with is that the increase in demand for living in places like NYC is much higher than KC, which is directly correlated (on average) to the quality of talent.
The assumption that top talent is coming from top tier cities has been challenged for the last decade and is only accelerating because of COVID.
My prediction is that there is going to be a convergence of salary values that are location agnostic. The only thing stopping this convergence is information asymmetry (e.g. companies know remote employees are happy to oblige to lower salaries because they lack negotiating acumen/power). This will change.