Wow, three articles today.
Thought I would provide some clarification on file sizes. They are important, absolutely. Not everyone has a server properly configured to support gzip. A minified file would need all that wire to transmit without compression.
Gzip is a super-compression technology available on many servers. Many servers provide that just to reduce their overall bandwidth needed to serve pages. The theoretical possible compression is 1048x. On most servers the typical compression ratio is around 1-to-7 with some types of files reaching 1-to-10 or slightly higher.
I ran some tests on the CSS Framework I am nearly finished. In raw mode, my CSS Framework comes in at 57Kb and minified is 46Kb. When it is gzip'd, it is about 8Kb (7,962 bytes).
I've complained about the file sizes of Bulma CSS Framework for some time now. To be fair to Bulma, I ran tests on their minified versions of both 0.9.4 and 1.0.0 and then gzip'd.
Bulma CSS v0.9.4 raw is 245.5Kb and 207.3Kb minified. V0.9.4 gzip'd is 27Kb.
Bulma CSS v1.0.0 raw is 729.8Kb and 647.5Kb minified. V1.0.0 gzip'd is 64.6Kb.
That is a significant compression (for all of these files) if gzip is enabled on the server. According to W3Techs, 51.1% of websites use gzip. That means that almost half of websites will serve up whatever CSS you provide. That will be minified if you provide that version, raw if you don't.
These CSS files and web fonts are before the page gets served. Add a few photos or graphics and your page could easily bloat beyond safe or reasonable sizes to aid in SEO. Yes, that's right. Large file sizes will impact your SEO.
According to the Search Engine Journal, the ideal page size in total is 33Kb. Beyond this and you end up with slower loading times, lost visitors, and decreased revenues. It's clear that your supporting files (CSS, fonts, etc) need to be optimized. You want the smallest possible file sizes.
EDIT: I have a hard time believing the research that shows 33Kb as the ideal page size. I suspect that is the final end product – fully loaded with CSS, web fonts, javascript, all HTML, images, photos. If we reverse the gzip compression ratios (estimating 1-to-10), I would suspect that a minified final page at 330Kb max to be more like it. By the way ... that suggests that minifying HTML would be important too – kind of defeats the purpose of using an HTML beautifier.