As of December 2021.
OS & Hardware
My main platform of choice has been macOS, since 2002 (and before, that, in the early 90s). I currently use a late-2013 15-inch MacBook Pro, for basically all workloads, professional and personal.
In a VMware-based virtual machine, I also run Windows.
My phone is an iPhone, for a number of reasons, including good sync + interoperability with a Mac (for example, if you have something open on one device and switch to the other, it will offer to open that for you). An increasing amount of tasks can be done just as well, if not better, on a phone than on a laptop.
I don't regularly use tablets, nor desktops.
Because I've been on a Mac laptop since 2002, my main input device is a trackpad, not a mouse. Apple's trackpads are good. Many others' trackpads are so bad they may have tainted your impression of what a trackpad can do. Acceleration, scrolling, gestures, palm detection. It's very cool to manipulate the cursor across vast distances while barely moving your hand at all.
For the same reason, I've also grown accustomed to somewhat low-travel keyboards. I average >100 wpm on TypeRacer, so I've probably made the right choice there.
Writing & Text
For quick notes (and who doesn't have a metric shitton of those), I mostly use Apple Notes. It's fast, syncs across my devices, supports images and checklists and folders and now also tags, and has pretty good search across years of notes, including OCR. Paste a screenshot of an error message, and it'll find it.
The one major thing it doesn't do is Markdown (or anything else nerd-y). For that, consider Bear.
But I don't really use Bear. Instead, for many, many years now, I use TextMate. It's this versatile old-school (at this point) text editor with merely OK support for autocomplete, but it launches very fast, my documents from the last session are right there, and for quick syntax highlighting (dozens of languages from Markdown to SQL to C#, community-extensible), text transformations, etc., it gets the job down really well. This is probably not a good programming environment by today's standards, but that's OK.