> • Nothing available that's as lightweight and good as Apple's "office"-type suite.

I personally create markdown documents in vis (a text editor like vim, but lighterweight — < 4 MB including optional syntax highlighting, and opens instantaneously enough that I use it to edit many of my HN comments, including this one, by pressing Control + I in my macOS-unsupporting browser) and can compile them to html with discount (< 1 MB) or to PDF, docx, reveal.js slides, etc with Pandoc. This is the peak of ‘lightweight and good’ to me. Apps like Abiword (an extremely lightweight WYSIWYG word processor, but I don't even know how tiny it is because it’s built in to the miniscule Puppy Linux distro that is currently running entirely in my RAM — making any traditional OS look bloated and sluggish to be constrained to run off a PCIE SSD at fastest) may better meet other people’s personal definitions of these words. Given the popularity of web “apps” like Google Docs, I think a native application like any in the LibreOffice suite is probably more efficient than most people care enough to notice.

> • Nothing as all-around good as Preview (yes, seriously).

Not having ever needed to fill out a PDF form, I won’t comment.

> • Worse battery life, partly due to worse OS optimizations and partly due to not having Safari available. Solutions to this in Linux that actually yield good results usually involve hard-capping performance at a pretty low level, IME.

“not having Safari available” — there are a million WebKit based browsers on Linux from the extremely Safari-like Gnome Web to Luakit to suckless Surf.

“hard-capping performance at a pretty low level” — Macbooks have their performance capped by cooling systems that can’t sustain high clock speeds anyway

> • Little things like screen recording and screenshot capabilities not being as nice for basic use, out of the box.

Speak for yourself, Simple Screen Recorder has been exactly that, simple and nice, out of the box, for me.¹

> • AFAIK not only is the default English keyboard on Linux far worse at the task of writing in English than that on macOS, there's not a single alternative layout that's close to as good as the Mac default. Yes, I'm dead serious about this, and frankly it's friggin' weird they'd have such a significant advantage on something like that in the year 2020, and I really wish other operating systems would catch up because I do not like being forced to use Apple products just so my experience composing documents in English isn't bad. I do not understand how they still have such a large advantage here, but somehow, they do. Totally baffling.

Like a sibling comment, I don't know what you’re talking about. However, I can say I love typing with my current layout.²

> • If you do anything serious with software-UI-related graphic design, or work closely with people who do, you pretty much need a Mac because odds are good you'll be using at least some mac-only software or have things shared with you that work only in mac programs.

~~ It’s too bad if this niche has failed to produce more portable programs. But I don’t see it as a failing of the OS for the vast majority of users.~~

elementary OS is itself a serious commercial software-related graphic design project. I am not aware of it’s designers using any macOS only software

> • You lose a variety of time-saving integrations with i-devices, if you're someone who takes advantage of those.

I don’t and I don’t see them as things to be taken advantage of by consumers as much as things to take advantage of and consume them and all their hardware-purchasing decisions through lock-in.

[1]: On the distro I use, PrintScreen instantly pops open a screenshot in a lightweight MS P
aint-style editor (mtpaint, which can crop with one shortcut). On ChromiumOS there’s one shortcut for fullscreen shot and one for drag-to-capture (Control + [Shift +] Show Apps IIRC), either one of which triggers a notification with a thumbnail of the shot that can be clicked to open the folder. I've also seen a small gui for taking shots of windows, areas, or the full screen with or without the cursor and/or a specifiable delay (on an old Puppy). I imagine elementaryOS has a very similar method to macOS, but I’ve never bothered to distro-hop to it because after using macOS for a while at school I didn’t miss it at home (it seems like a good OS only compared to Windows).

[2]: Eg. I can type a superscript one simply by tapping <Compose> 
 <1>, where Compose is mapped to tapping my left shift key. IIUC this would require installing third-party software like Karabiner Elements on macOS.