Word of warning: I tried Marissa Mayer's Sunshine contacts and it nuked my phone's contacts. Luckily I had a backup vcard export from way back I could restore from.
Others I've tried:
* Clay (https://clay.earth) is a great option for "batteries included". Based on what you described, it can pull from Google/Outlook, Linkedin, and messaging apps. Doesn't get all the duplicates but gets close enough, and they offer carddav for 2-way sync to phone.
* Monica (http://monicahq.com) works for more barebones and self-hosted. They were working on a new version, not sure if it was ever merged into main product. I tried it once and it ended up being more of a gift and birthdays-focused notes app for me, but YMMV.
* Otherwise a Notion doc or spreadsheet might be enough! Especially if you start with an export from something else.