Not because owners don't want one. Because a good one costs $70–90K a year plus benefits — and at $1M–$3M in collections, that's a hard number to justify. So the business side runs on default: you, between patients, plus whoever picked up each task first.
Everyone tells you the fix is to hire one anyway. Find a superstar. Train them. Hand it all over. But now the practice depends on one person — and if they leave, everything they carried leaves with them. Owners who've lived that once rarely want to live it twice.
Here's the truth: you don't need a manager yet. You need structure. Structure runs a practice at this size — and a manager can come later, when the practice has grown into one.