information design – What are the usual techniques for dealing with too much data that is still needed

I work in a company where the operations team uses a dashboard to manage / monitor logistics operations. In order not to make this problem specific to operations or logistics, I want to put it in generic terms: here is what the dashboard looks like at a high level (intentional blur for reasons of confidentiality):
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The problem is that now the page is getting very slow on the browser. I did some scans and performed on the weak laptops of our staff, the page load is too heavy (it works fine on my very expensive pro 2018 macbook, but it's not scalable) .

Whenever I ask someone he's there need all the information on this page, they answer yes! each last piece.

My question is this: Can any one say me literature, terminology, case studies, etc.? to know how to handle this situation? Do not forget that I am not an UX professional, but I have worked in areas that overlap for most of my life.