Casinos are a business and businesses are built to be profitable. If the Casino is losing money overall, it won't be open for long. So yes, Casinos are built to make money. People can win and be profitable but there are way more losers.
They need profits in order to satisfy the shareholders, and pay the expenses.
Take for example a bitcoin webcasino, they have a website to run (hosting fee + domain fee), they have to pay their programmers and their marketing team, or their support team. There are many expenses. And then what is left is distributed to the shareholders, wheareas in many casinos people can invest.
And all of this is based on that 0.5% house edge, so that is necessary to keep the casino open.
But other than that, it's a transfer of money from unlucky people to lucky people.