Not sure if they even think they need to prove their assertions, after all Musk (same as his "boss"/BFF) has made the most outlandish claims without a shred of evidence (the "radical-left Marxist vipers" at USAID). To me it looks more like they are already 100% convinced that any work done by federal employees is completely worthless, so they can indiscriminately fire anyone they wish without doing any harm. Same for the attrition tactics - they tell people to return to the office and at the same time end leases for offices etc.