My biggest pet peeves are (a) when mature software or mature organizations pretend they are a three person startup and refuse to document anything and have meetings all day (b) when product owners say f the existing architecture or tech debt and literally tell you to rip out everything and install a new tech stack because it is agile.

These morons know nothing and bark out orders based on their agile bonafides which is nothing more than snake oil. A magical cure all irrespective of the problem you are trying to solve.