An injured client doesn't complain. They just go quiet.
Pain shows up. They get cautious, then scared. They skip a session, then a week. They don't tell you they're stopping, they just stop replying. And the client you spent months building a relationship with is gone.
The advice they get doesn't help either. A local physio who has never programmed a training block tells them to stop deadlifting for six weeks. You never hear about it. Now your client is caught between two people who disagree and don't speak to each other.
Losing three clients a year to injury, at €200 a month, is somewhere between €3,600 and €7,200 you never see. Keeping one of them three months longer pays for itself many times over.