First. What do you say about prevention of the formation of unions? Who benefits from that? The owners of the companies certainly do. Are they stealing though? No. Is it still a problem and making inequality bigger? Yes, because then workers have no negotiating power and have to accept whatever salary they are offered. In the limit, that salary could be food, water and shelter, and we'd be back at slavery.
Second. If you have 1B to invest, and I have 1k to invest and we both invest... there is no stealing, and you're getting richer much faster than me. Now you're not to blame for having that money, or investing it, but it is undeniable that the wealth inequality between the two of us is only ever going to grow, all things equal.
Third. Ever heard of lobbying? Who do you think lobbies and for what purpose? Hey, Let's use the free market and have people pay as much as they can for insulin. Let's make it legal to do that. Let's say that's 500€/month. Welp. A poor person just lost half their monthly savings. A rich guy? Barely a blip. You know who's also a rich guy? The owner and co. of the company of makes insulin. Where is the stealing?
Cmon. Saying that unless there is stealing then it's ok is so uninformed I have no words for.