resume should not be a laundry list of everything someone has done in every role. someone who has been in a company for 5 years is not going to have 5 times as many bullets as someone who was there 1 year, you pick and choose the relevant points for the role, and for a generic resume you pick the most important things.
secondly it should not be about tasks, but accomplishments..maybe have a short summary of what the role was, and then bullet points ion key accomplishments. if I am hiring a marketing communications manager, I know basically what they do, so telling me what they did in 5 lines vs 20 lines is not going to do anything. a descriptor of the role and a handful of key accomplishments so I can gauge how you compare to 10 other marketing communications managers
I can not stress enough the importance of understanding that niether a company recruiter nor a hiring manager are going to go through an entire resume line by line word for word. Unless and until they are extremely interested, and volume does not build interest, but what accomplishments we see, how well the person is suited for the role.
so dont make people draw their conclusions, state who you are and what you bring..and start that with a key skills or summary section at the top..which should not again be a laundry list of everything but list key skills in order of your aptitude in them and their relevance to the role. if it is a generic resume then of skills in importance and relevance to the industry or type of role.
lastly, your last few years experience is much more relevant and of interest than what you did 10 years ago, because tings were different, you had a junior role, so if someone is hiring a CFO, do they really need to know 10 things that the person did 15 years ago as a financial analyst straight out of college?
so..focus on key successes, focus on recent roles..and less and less on older roles. internships which got 5 bullets, get 2, and eventually all internships get listed as one line somewhere etc.
academia and research etc are different, and even there things are changing.