This might be true, and I agree SWE should always push for getting a decent slice of the pie. However how much of the 'value' is establishing a monopoly in some area of tech, rather than the tech itself. The mysterious "good will" or "intangible assets" of the brand value, institutional knowledge, having the right software and hardware in one place etc.
There is only one Google, but there are plenty of bright people who are capable of learning SWE.
If all the little tech companies were making $1m revenue per SWE too, then yes you'd probably see tech wages raise in line with that.
However those little tech companies haven't solved traction and growth yet (if they are aiming to at all), so they can't compete with SV and stay profitable. They don't have $100M in funding to throw into salaries.
Or from another angle - a individual SWE starting their own mini SaaS makes $2k a month. They are happy for this as a start, but on the other hand they are extremely underpaid!
An analogy - shouldn't Amazon warehouse workers be on double what they are paid, as without them Amazon can't ship anything!
At the extreme, workers getting the full value of what they are putting in would be something different to a corp, more like a co-op.