I wish this misguided notion regarding "inofficial strict mode" would go away, as `set -e` is suboptimal (and can be very tedious to deal with on top of that): https://mywiki.wooledge.org/BashFAQ/105
It makes sense to opt into errexit for select blocks/sections in scripts and under certain circumstances, but having it default-on is a recipe for quite a bit of head-scratching in the future.