Compared to the ancient world of EBCDIC versus ASCII versus various ISO standards versus country-defined encodings versus Extended EBCDIC code pages versus Extended ASCII code pages which varied depending on operating system, nearest flag pole, network adapter, time of day, etc…: Unicode will forever be a simpler walk in the park.

It's complexity is a relief compared to where we've been. It's definitely not simple, but it will forever be far simpler than what our grandmothers had to work with if they were writing international software.

Give the "Indic scripts" section of https://manishearth.github.io/blog/2017/01/15/breaking-our-l... a read.

TL;DR: Unicode is complicated because some non-Latin writing systems are complicated and those non-Latin writing systems account for over a quarter of the world's population. (They're either majority or present in India, Indonesia, Pakistan, Bangladesh, the Philippines, etc.)