Every byte sent will cost the business. If you can save that 2MB per user per cache life, you pay that much less on the internet bill for your hosting.
Every byte sent uses up some of your limited bandwidth while it is being sent. If your site is 10KB and you rely on 2MB of javascript libraries and fonts, offloading that 2MB is quite a significant reduction is resource usage.
These above two views seem vastly more important than terminal laziness, up-time management, etc.
Ah yes - I remember those _dark days_ of being a shared webhosting customer over a decade ago and stressing about breaking my 500GB/mo data transfer limit.
Today, Azure's outbound data costs on the order of $0.08/GB, so 1MB is $0.000078125, so the cost of 2MB of JS is $0.00015625.
Supposing you have one million new visitors every month (i.e. nothing's cached at their end so they'll download the full 2MB) - those one million visitors will cost you $156.25 in data-transfer.
Compare that to the immediate cost to the business of paying their SWEs and SREs to trim down the site's resources to a more realistic few-hundred-KB, supposing that's a good 2-3 week project for 3-4 people - assuming a W/Best Coast company, that's ( $250k / 52 ) * 3 * 4 == $57,000.
From looking at those numbers, there is absolutely no business case in optimizing web content - it's now significantly cheaper (on paper) to have a crappy UX and slow load-times than it is to fix it.