I use both and I don't think Sheets is anywhere close to a substitute for excel if you're a power user. If you are a fairly basic user of excel, Sheets should be fine. I think collaboration works better in Sheets.
If you really prefer Outlook (which I do, but probably primarily because I'm used to it), there's nothing stopping you from using Outlook for email if you are using Google Workspace. There is a Google plugin for Outlook that will easily authenticate all of your Google accounts. If the primary gripe is how the Google web interface deals with email, that's easily solved be simply installing Outlook.
I've also found Drive for Desktop works perfectly well with MS Office files. I loathe Dropbox. OneDrive obviously integrates much better with MS Office.
If you really prefer Outlook (which I do, but probably primarily because I'm used to it), there's nothing stopping you from using Outlook for email if you are using Google Workspace. There is a Google plugin for Outlook that will easily authenticate all of your Google accounts. If the primary gripe is how the Google web interface deals with email, that's easily solved be simply installing Outlook.
I've also found Drive for Desktop works perfectly well with MS Office files. I loathe Dropbox. OneDrive obviously integrates much better with MS Office.