If the firm(s) you are referring to are registered futures proprietary trading firm(s) - you're really confused and misinformed about their business model and indeed the requirements set forth for those firms to exist by the regulated futures exchanges. There are actually some very good reasons to trade as a proprietary futures trading firm employee - at least in the United States. I'm not sure if the rules are different for European firms.
Here in the United States, you are typically splitting your net profits 50/50 with the firm. But you are only risking the firm's capital. You are paid as an employee on an IRS Form W-2 here in the United States.
It's not easy getting into these firms here in Chicago or New York City. They are looking for sharp traders who they can lever to the maximum. I know most of these firms here in the States and they are very professional well managed trading firms. And they're not looking to train newbies. If you don't have a trading strategy and plan that they like and that they feel they can lever don't even bother.
https://www.cmegroup.com/company/membership/files/ECMQA.pdf
"Eligible Firms: Proprietary trading groups are eligible for ECM.
They will receive discounted fees for all electronic trading in the accounts of the proprietary trading firm conducted in accordance with CME Group policies. Please note CME Group may be unable to accept participants located in certain countries. Please contact the CME Group Membership Concierge Team for further information regarding any location restrictions.
5. What guidelines are used to determine if trading is proprietary?
A proprietary account is evidenced through:
• All profits and losses of the account are included in the income of the firm.
• All profits and losses of the account are taxed to the firm.
• The trader (non-owner) does not make any capital contribution to the account.
• Only the firm’s capital is at risk of loss; no traders may make any contributions or payments to the firm nor have any capital at risk.
• All trading activity must be solely for the benefit of the ECM. No other individuals or entities can have any ownership interest in the ECM’s proprietary accounts.
• All funds contributed to and traded under the ECM are subject to loss from any and all trading activity of the ECM."