What non-FOSS software have you been unable to quit?
For me, Google video search, Google books (Internet Archive is good, but doesn't always have the same stuff), Adobe InDesign (but in the process of learning LaTeX), and Typewise. As for the Google stuff, I liked Whoogle a lot, but almost all their instances seem to have been blocked or shut down. Also, apologies if this is repeating an earlier post.
Google Maps. It sucks, and stores randomly pop in and out while you're trying to zoom in past the McDonalds ad that's showing despite you searching "shoe store", but it has so much more info than the competitors that they don't compare.
WhatsApp: I have been unable to convince my family and friends to use any other platform. Plus. in alot of countries, having WhatsApp becomes a must.
Office 365: The only option I can use for work including Outlook and Teams.
Google Maps: I keep trying to use OsmAnd+ but it is almost impossible to search for addresses.
I don't understand why we spend so much time praising proprietary software in these communities.
As to your question, I have a separate Windows machine for gaming, but that's it. I keep one foot in the free world and one in the proprietary. As for productivity tools I can't think of a proprietary tool I "can't quit" or that I would pick in favor of a free tool.
Fans of proprietary software have this weird belief that free software users choose inferior tools for purist or idealist reasons. This is offensively ignorant. No one chooses bad tools on purpose; we just consider freedom to be part of the criteria of a good tool.
I was using Norton Commander in DOS in the 90s, then WindowsCommander in Windows 3, which was renamed TotalCommander. Using this for maybe 35 years. I don't know how to use Windows gui to copy/paste or explore multiple folders etc.
Solidworks - A reliable FOSS 3D CAD package would be amazing... Parametric Blender?
Photoshop/Illustrator - I know how to do 50% of what I need to in GIMP/Inkscape, but I lean on Adobe usually!
Discord has friends locked in. IRCcloud is so convenient. Tap to pay app is too useful. The app that controls my heat and AC is going to be a big project to replace. Spotify has family locked in. All the garbage running on my car would be nearly impossible to change.
GBoard is one I've tried to ditch a few times and end up coming back to. :(
Google maps, venmo, and lyft are my last real holdouts.
I tried Osmand~ but it like using your dads Garmin from 2005. The last two have been hard to find good alternatives to. Would be nice if signal payments were in a stable coin instead of a shitcoin.
Games, for everything else I've found a foss alternative that I prefer. I will do a google search once every couple of days if I'm really struggling to find something but even as a last resort search engine it's been getting worse - I heard they put an ad person in charge of search... so that would probably explain that descent.
Just a comment -- for InDesign-type work, I find something like Inkscape (or Scribus) easier to work with than LaTeX. I usually only use LaTeX for things where the layout needs to be pretty but not customized. Its possible to use it for design, but not a good use of time.
Reaper DAW, and I have no plans on replacing because I like it. Also Reason, which I do have plans on replacing, but with what I haven't a clue. Unfortunately, audio continues to lag way behind on Linux and open source. Additionally, VST is unfortunately THE standard for audio plugins, and they are indispensable in audio production.
I also run a lot of proprietary stuff like Discord or Instagram due to peer pressure but I let it slide and put my hopes on Android sandboxing the apps and GrapheneOS tweaks. In my opinion, making sure that proprietary app can't reliably access your data and never giving it anything sensitive yourself is a decent risk model.
The only proprietary software I use and somewhat trust is Obdisian. Honestly, it's just excellent and I can't see myself moving away from it anytime soon.
FolderSync on android. It's the only automatic sync application I've found that syncs to mydrive.ch.
Also a couple of UI apps, BarLauncher, which is a notification thing that let's you put app icons to launch from the notification drop down, and LaunchyWidget, like a scrolling "fence" to dump app icons in on your home screen. They're both so simple, I'm surprised that nobody has built FOSS versions of them.
On my PC I don't use any proprietary software at all.
Square Launcher on Android. Tried a whole bunch of other launchers but keep coming back to the windows tile interface. Scrollable vertically and horizontally puts so much within reach so quickly.
Clip Studio Paint
IIt was way ahead than any commercial or FOSS alternative. Especially if you're illustrator or comic artist working in specialized workflow (East Asia and SEA industry).
Tried Krita back then, but still lacks a lot of major important feature and customizable UI layout.
Obsidian. Plain text files with as many or as few plugins as you want. All versions of the app look and behave the same (other than mobile, but at least android is kinda close). Nothing stored in a database file, no manipulation of the text files themselves (looking at you, Joplin). I'm open to another option but so far, nothing is as elegant and platform agnostic as Obsidian.
One thing I really liked but quit because it wasn't FOSS was WorkFlowy. I did try logseq a while back and thought it was ok, but had too many other bells and whistles in addition to what I really wanted which was just a collapsible list with infinite hierarchical depth. I really wish someone would add this functionality to an email client like Thunderbird as part of its tasks.