Wikipedia administrators are vital to the project’s success, performing over a million administrative actions annually. This multi-method study systematically analyzes adminship across 284 Wikipedia languages since 2018, revealing a critical two-sided trend: while over half of all Wikipedias show a net increase in administrators, almost two-thirds of highly active Wikipedias face decline. Our analysis, drawing from large-scale adminship log analysis, over 3000 surveys, and 12 interviews, reveals this decline is primarily driven by insufficient recruitment, not unusual attrition. We identify key barriers for potential administrators: limited awareness, ambiguous requirements, a demanding selection process, and low initial interest. Recognizing that current administrators remain highly motivated and engaged, we propose actionable recommendations to strengthen recruitment pipelines and fuel Wikipedia administrator growth, crucial for Wikipedia’s long-term sustainability.