What's your favorite software to manage contacts?

HI everyone, I'm currently building folk that is a contact management software for teams and would love to know what folks are using to manage personal contacts? I've seen many options but none seems to stick - Spreadsheets (eg Notion, Airtable, Coda, even Excel) but that are not really made for contacts - Contact managers such as Google Contact or Contacts+ but really lack collaboration - Tweaking CRMs such as Salesforce, Hubspot, Cloze but that are maybe too heavy for this purpose Any idea?