There's `brew uninstall --zap $application`[1], and there's pretty decent coverage, but it's by no means comprehensive. If you feel inclined to contribute, the process is quite streamlined, and there's a helper script[2].
I used Appcleaner[3] for many years, and it's still perfectly serviceable
I'm keeping my eye on Pearcleaner[4], which is additionally open-source and written in Swift.
I followed a similar path as you did about a year ago. Having tried a bunch of options, I can recommend strongly Strongbox - fantastic native apps for iOS and macOS, with your choice of sync mechanism (local-only is also a first class citizen), and it uses the KeePass file format so you can use your client of choice on other operating systems/no worries about lock-in. Good system integration and autofill extensions. I also appreciated that there was an option for a one-time purchase.
I used Appcleaner[3] for many years, and it's still perfectly serviceable
I'm keeping my eye on Pearcleaner[4], which is additionally open-source and written in Swift.
[1] https://docs.brew.sh/Cask-Cookbook#stanza-zap
[2] https://github.com/nrlquaker/homebrew-createzap
[3] https://freemacsoft.net/appcleaner/
[4] https://itsalin.com/appInfo/?id=pearcleaner