Hello,
If you look to the datasheet of (for example) a BC847/547, then you will see that the small signal hfe depends on collector bias current.
hfe@ 1uA > 100 (guessed).
hfe@ 1mA = 190
hfe@ 10mA = 185
hfe@ 100 mA = 80.
If your momentary current (that is AC peak + bais) peaks significantly above 10 mA, Ic is no longer 180*Ib.
In many large signal application, the peak collector current has excursions that are in the region where hfe is low and therefore the "effective" hfe for large signal applications is less then for small signal applications where the bias current is in the region of high hfe.
Also when using transistors at low current (say below 10 uA), the small signal current gain can be significantly below the value for moderate current.
Nowadays there are small signal transistors (not darlingtons) that have exceptional high hfe and low saturation voltage, even at current > 1A.