Three reasons, roughly in order: no support structure after the certificate (the confidence cliff), the slow first year outlasting their patience or cash, and discovering they do not enjoy injecting. Only the third is a good reason. The first two are solvable with supervision, honest financial planning and keeping the day job.
The sector’s quiet statistic is how many certificates never meet a paying patient. One provider admits nearly half its students are retraining after being failed elsewhere, and forum threads are full of practitioners who trained, froze at the edge of independent practice, and drifted back to safety.
The fixes are unglamorous: a first-90-days structure, a named mentor, case-review calls, scope discipline, and a financial plan that assumes the slow year the data describes. That is the machinery in after the certificate, and it is why our courses end with a competency record and a support calendar rather than a handshake.