The missing camera light seems pretty serious. Any sandbox escape can turn on the camera and record without you noticing. Or your school or employer could. If you're in full screen mode the menu bar is hidden too. It's a very strange move for privacy centered Apple.
The indicators are controlled along with sensor access at a very low level within a secure “exclave” from the main kernel; this is how the on-screen indicators have worked on iPhones for a few years. The indicator is rendered within the display controller at the firmware level, so can’t be affected by anything in _either_ user mode or kernel mode. [1][2]
It's not just the menu bar icon (which can definitely be spoofed), but an on screen dot where the system is controlling pixels directly bypassing any OS level drawing on the screen.
