If there's a new contact in HubSpot or any other CRM or Google Contact ➡️ Add the contact also to another CRM, Spreadsheet, CMS
Or add to Salesforce or any other marketing tool as most of them have a nice API these days.
Or run some marketing automation logic straight from the N8N. For example, send the second email after 3 days and if no reply then WhatsApp message in 7 days unless it is the weekend and should wait till Monday.