there’s only one certainty in life since birth — death.
but the time in-between birth to death is unknown to the individual (while some pple may argue that some higher beings/deities know/control/pre-determined it).
what would then one need to do to pass the time in-between?
ironically, the first thing is to find sustenance, to sustain the ever-dying shell; regardless if you are humans or prokaryotes, you do the same. in the grown up world context, it would mean “earning a living”, for most is to find a job(s) to earn an income to find sustenance and obtain things, to prevent the shell from dying too fast.
when one is able to find sustenance, and there’s still energy and time and not yet time to rest/sleep to regain energy for finding sustenance, pple begin to choose things to do (e.g., entertainment, interests, hobbies).
and life goes on like that, day in day out, excluding ‘sudden death’ events, the shell slowly crawls towards the certainty.
so back to the question, 芸芸众生，日日忙忙碌碌何为？the answer is perhaps 为了不死，或知道会死但不要想太多？
so what’s death? would death means ‘nothing’ at t+1? i wouldnt know for sure, but perhaps ‘nothing’ is the conception for those who seek early ‘termination’ on the journey to certainty?
different religions (generally defined as a set of beliefs, practices, and moral codes that relate to the nature of the universe and the place of individuals within it) would have shed different lights on the question of “芸芸众生，日日忙忙碌碌何为？”. from a buddhist perspective, one is trapped in the worldly cycle of death and rebirth (aka samsara). and one truth in this trap is suffering (dukkha), which can refer to “direct suffering, being liable to suffering, a bodily painful feeling, or unsatisfactoriness, deficiency, insufficiency.” not sure if there’s another religion where suffering is absent, not there at all?
how to attain the end of suffering, the end of the cycle, and thus the 芸芸众生，日日忙忙碌碌? it would be to work towards enlightenment through eliminating ignorance and craving. the method is to follow the eightfold path (八正道): right understanding, right intention, right speech, right action, right livelihood, right effort, right mindfulness, and right concentration.
so if you are a 芸芸众生 like me reading this in the midst of 日日忙忙碌碌, perhaps you can find a way in your (religious) beliefs to explain the purpose of your 日日忙忙碌碌 and if there’s a way to seek an end to it, of cos unless you love work so much and also there’s no ‘suffering’ in life. for me, the eightfold path (八正道) would be a good start, if not a reminder (:
references:
https://www.britannica.com/topic/Buddhism/The-Four-Noble-Truths
https://www.bbc.co.uk/bitesize/guides/zg7297h/revision/3
https://www.bbc.co.uk/bitesize/guides/zyhmk2p/revision/1