You're 100% right. uBlock Origin can reduce page weight by an astronomical amount.

uMatrix (unsupported but still works) reduces page weight and compute even more

How so?

it allows javascript on the original site domain, but turns it off for external domains, buts then lets you selectively turn it back on, and remembers what you've selected. Turning off javascript turns off a lot of both addtional downloading and cpu cycles. for impatient people it's tedious, but for minimalists it's heaven.

If you enable the Advanced Features mode of Ublock Origin you get access to just about all the things uMatrix does

Except for a usable UI.

And disabling JavaScript

I strongly suspect that the venn diagram of people that know how to minimize data usage, and indigent people being given free cell phones with limited data has precious little overlap.

Yes, but "qingcharles" said he works with them, so he can show it to them.