YES, it's possible without any CLouds.
Even in 2020 it's a "problem" to sync Android notes, adresses, dates etc with Ubuntu without using any clouds, especially US-american data gathering clouds.
Here's what I did (basement is UBUNTU 18.04 and Samsung S7):
Install CompanionLink on Android cellphone (free)
Install CompanionLink via WINE (because it's Windows Software) on Ubuntu
(you need to pay a little fee for the Windows version of CompanionLink)
Install an old MS-Office Pro 2007 also via WINE on Ubuntu
Create the same User (like your mailbox on Android) in MS-Office
fill it with at least one contact, date, note, task.
Start CompanionLink and adjust the type sync-method you prefer
(wifi, usb or companion-cloud)
Hint: I onyl use direct way via WIFI because I never use anykind of clouds to keep my data private.
First sync should be ANDROID to Outlook no deletions at all!!!!
When this is done, you may create new items in each of them.
According to your subsequent adjustments how to sync, it will sync all latest updates visversa. (simply learn all options CompanioLink provides)
So, be happy or die in the linux-jungle ;o))