Connecting Client Non-Organic Platforms

I have recently gone from creating 2-3 websites a year to around 15 last year. This increase has shined some light on an area where I seem to be stuck! What is the best way to connect a client's social media pages and any non-organic platforms? Do you simply ask for all of the username/passwords? I used to have my clients add me as an admin to their social pages, but that seems like a clunky and outdated way to do business.

I have been using a white-label social media platform that has a fantastic tool. I can send an email to my client that they can fill out their username/passwords for all of their social pages and it automatically syncs so I can access them from my platform. Does Squarespace have something similar? Is there something else you are using?

Thanks in advance for any help.

Chris