The 'timing' of already-rendered audio is sample-accurate. Thats immutable. One audio sample per timing subdivision. It runs at the sample rate, and as such, visually, its timing can be displayed exactly if you soom in sufficiently.

The internal timing of MIDI events, however, has nothing to do with the sample rate. Ultimately, it has to be quantized to that sample rate for playback purposes, but it doesnt run nearly that fast.

MIDI events are driven by a clock which is measured in pulses per quarter note. In a modern DAW ppqn is typically set at values like 480, although that's something which can be altered. The further complication of that is that ppqn is derived from the tempo, not the sample rate.

And then you have quantization on, to 64ths, or 32nds, or 16ths.