Author here. Post is a bit rambling but I just wanted to document somewhere the things I encountered along the way with links to resources, to save someone having to trawl the web for it next time.
Also, just remembered another neat piece of software: flameshot. It’s basically macOS’s screenshot editor but even better IMO. I’m not sure whether you can bind it to macOS keyboard shortcuts though.
I'm the guy from the sway github issue mentioning that the chrome autoscaling had been fixed, so maybe you need a more up to date chrome, or maybe there was some kind of regression. (I had some other bug with sway to do with the tray, so haven't been using it).
One other suggestion for an alfred/spotlight alternative is dmenu (or bemenu for a wayland compatible one if you go for sway), there's also rofi as an option which does the same thing iirc.
The real problem with wayland are all the apps that just don't support it. From emacs, to, e.g., all the electron apps built with older versions of chromium, etc. You can use them seamlessly with Xwayland, but then a lot of things work "weirdly", e.g., HiDPI displays blurry Xwayland apps, applications like obs-studio cannot record some apps, etc.
The the Sway ecosystem main drawbacks are the immaturity of the tools (e.g., waybar (i3bar replacement), wofi (rofi replacement), etc.) and the drawbacks of wlroots (e.g. lack of nvidia support in contrast to gnome and kde, etc.).
Many things kind of "just work" under Wayland, but many things also kind of just don't properly work. Using pipewire to, e.g., stream desktop apps via webchat from firefox/chrome works weirdly, streaming one monitor or one sway workspace from firefox/chrome does not work, capturing one workspace from sway using obs studio in another workspace does not work, etc.
I hope that fullscreen desktop sharing "just works" now that we've released xdg-desktop-portal-wlr[0]. If you have any trouble with it, hit me up on freenode #sway or raise an issue on this project. We're happy to help and looking for a broader user base to help us test it out.