Ask where a logo will be seen and most answers describe a signboard, a business card, a van. In practice the most frequent appearance is sixteen pixels wide, in a browser tab, next to eleven other tabs.
What breaks at small sizes
Three things, almost always: fine strokes disappear, tight counters (the enclosed spaces in letters like a and e) fill in and turn to mud, and gradients band into flat colour. A mark that depends on any of those is a mark that only exists at large sizes.
The test
Export the logo at 16, 32 and 48 pixels. Look at it on a light and a dark background. If you cannot tell what it is at 32 pixels, it is not finished — and no amount of care on the large version will rescue it.
What we deliver instead
A primary lockup for the cases with room, plus a reduced mark that survives being small: heavier strokes, opened counters, flat colour. Same identity, drawn twice, because one drawing cannot do both jobs.