Yes, the stock market is open to everyone. But there is a difference between being able to trade only 50 EUR or 50,000 EUR, because fees often have a fixed component and are capped at the top. So the 50 EUR trader pays a fee of 4.90 EUR, while the 50,000 EUR trader might pay 25 EUR. The 50 EUR trader therefore has to make a 10% profit just to break even, as the saying goes. And 10% profit is quite ambitious if you think long-term. Many funds cannot achieve that, for a lot of money...
Also with savings accounts... banks currently pass on the good interest rates only to new customers. Existing customers get nothing, especially old people with savings balances who are overwhelmed or would be overwhelmed by constantly switching banks.
And capital gains are taxed at 25%, while income is taxed at up to 45%. My marginal tax rate is certainly higher than 25%, meaning my productive work is less worthwhile than if I had inherited and lived off the capital gains...
Let's not even start on inheritances. There is plenty of evidence that a low inheritance tax increasingly concentrates capital at the top over generations. All sufficiently studied.
So please stop your class struggle...