Why Baudot is a 5-bit code, so it has only 2^5 = 32 possible combinations, not enough for letters, numbers and punctuation at once. To get around that, it reserves two of those combinations as shift codes, LTRS and FIGS, which switch the receiver between the letters case and the figures/punctuation case. ASCII uses 7 bits (128 combinations, or 8 bits in extended versions), which is plenty to give every letter, digit and symbol its own unique code, so no shift characters are needed.
Watch out The choices that put the letters/figures shift in ASCII have it backwards, and the 4-, 6- and 7-bit counts for Baudot are simply wrong; classic RTTY Baudot is always 5 bits.
Baudot = 5 bits + 2 shifts (LTRS/FIGS); ASCII = 7 bits, no shifting needed.