Workers savings doesn’t change the fundamental dynamic. Their savings are dwarfed by those of their bosses. So when stocks double, workers, even accounting for savings, benefit far less in absolute terms than owners. Assets under capitalism follow a Pareto distribution - a minority owns a majority of the wealth.

And having $100 in savings doesn’t free someone from wage labor.

Indeed. At the bottom of the income ladder, $100 is critical. Lots of surprise bills can be more than that, and failing to pay them can cause further income reductions. This is why I support a strong welfare system: it lets everyone survive when things hit the fan.

But if you can put aside $100 per month, for a while now it's been possible to put even that little into the stock market. Exact growth is highly variable and depends on what you actually invest in, but it's not implausible that over 20 years, less than half a normal working lifespan, this would have turned $24k spend into $70k present value. It's not the millionaire's club, but it's a lot for someone who only had $100 they could stand to put aside each month.

I wouldn't recommend anyone puts their last $100 into the stock market, or even to let themselves dip bellow $1000 in cash at any point unless they're in an extremely low cost of living nation.

To get big money, you need to start your own successful business. But still, investing in stocks can make you quite comfortable.