Does 24-bit vs 16-bit actually matter?

For recording, yes — as headroom, not “quality”. 24-bit gives ~144dB of theoretical dynamic range versus 96dB, so you can record at conservative levels (~−18dBFS average) without the noise floor creeping up. Every modern interface records 24-bit, so this costs nothing. For finished listening, 16-bit already exceeds any living room’s noise floor; nobody honest claims to hear the difference on playback.