Which CRM has the best “ecosystem” for adding/managing contacts?

I'm referring to browser extensions etc to make it very pain free to add and organize contacts within other applications. Thinking also of non-functional aspects like loading speed of the browser extensions, ease of use, ability to add by email only, etc

I've tried some personal CRMs like Dex and Clay as well as more formal CRMs like Hubspot and Folk but it feels like I haven't found the best solution yet.

TIA!