This is an update to 2023-11-21 with somewhat interesting changes.

3rd party, roughly in descending order of use

Keyboard Maestrokeyboard shortcuts & macros across all apps
Default Folderrapid navigation in open/save dialogs
iStat Menuskeeping me informed about network & CPU activity
Command X⌘-x (followed by ⌘-v) in the Finder
BBEditall unformatted editing
GraphicConvertergraphics Swiss Army knife, occasionally helped by Pixelmator
Reederdaily news on topics I find interesting
Houdah SpotSearching → Finding! Better than Spotlight
PDF Squeezer PDFs much smaller without visible loss, can also export images(!)
ImageOptimimage optimiser for jpg, png
VinegarYouTube without hassle
SilentKnightdaily check on security (and other) updates
Jekyllstatic CMS for all websites I author/maintain
iReal Promaking music
Guitar Promaking music
MacGiroaccessing my bank account securely
Zoteroscience: citation management
OcenAudioediting & transcoding audio
↓ Faded out ↓ 
AlfredButler → Alfred → Keyboard Maestro
BusyCal/Contactsdue to high costs, I fell back to the built-in solutions
StrongboxSherlocked by Apple
CopyClipSherlocked
Al Dente (pro)soon to be Sherlocked
UPDFtoo pricey (same for PDF Expert)

Apps from Apple

Mailsince several decades
Safaribrowsing, of course; keep Firefox, Chrome, etc., always in the dock too
Pageshalf of my (formatted) editing in Pages, especially layouting
Calender good enough
Contatcsgood enough
Notesquick notes, quick lookup; tried Obsidian
Numberssome of my spreadsheet work
Keynotefor (nearly) all my (>900 so far) presentations
Previewpoor name, good capabilities
Passwordsmarkedly improved, now fulfills all my needs
Booksfor reading & audiobooks. HORRIBLE interface,
getting worse every year, keeps getting worse
Mapsby now nearly eye-level with Google Maps
Musicgood, though annoyingly pushy with ads,
interface getting worse every year
Home(too) slowly improving, still not improving
Photosgood
QuickTime Playerstill my preferred video editor
Time Machinemarkedly improved, slow over WLAN (helped to switch to the 5 GHz band)
Xcodegood for programming

Unrelated – Adam Engst’s great collection of “fn” or 🌐 key shortcuts

🌐-ASelects an item in the Dock, after which you can use the arrow keys to select different items and press Return to switch to the app
🌐-⇧-AOpens Launchpad
🌐-COpens Control Center
🌐-DStarts dictation (or set a modifier key to do this when you press it twice)
🌐-EOpens the emoji picker (same as choosing Edit > Emoji & Symbols)
🌐-FToggles full-screen mode
🌐-HHides current windows to reveal the desktop; a second press restores them
🌐-MSelects the ⌘ menu, after which you can use the arrow keys to navigate menus and activate the selected command by pressing Return
🌐-NDisplays Notification Center
🌐-QStarts a new Quick Note in Notes
🌐-⌫Forward delete on keyboards without a Forward Delete key⌦ (or use ^D)
🌐-⏎Equivalent to the Enter key on the numeric keypad, which is slightly different than Return⏎ in certain contexts
🌐 ↑Scroll up one page (same as the Page Up key)
🌐 ↓Scroll down one page (same as the Page Down key)
🌐 ←Scroll to the beginning of a document (same as the Home key)
🌐 →        Scroll to the end of a document (same as the End key)

(Nearly) unrelated…

All glyphs for Apple’s special symbols