You are lucky Angela, never to have used either.
However, Couple of months ago I went down the rabbit hole.
And its not just FB and Twitter... Its everyone...
For reference if you use any Google service... go and click the links on privacy and view the info Google has on you. Since EU fined them last year... you can do that.
You can view the files of yourself, geo-location data, autofill data, search data. They knew better where and when I had been then even my own memory.
The thing is... The way marketing works... Third party companies buy all your data. And first party companies (FB for example) collects data on people that do not even use the service... (Zuckerberg congressional hearing, EU Zuckerberg hearing for reference)
I used a service I can't find anymore, last year... It was a site with templates ready to send to 3d party Advertisers to delete the stored files on you... (which I never agreed to being with, must have been buried in FB terms of service among the gibberish) I am talking billion dollar companies... having a bunch of data on me... without me ever being made aware, in good faith.
I used it... and only like 8 / 30 3D party services removed my data. The rest gave me some BS errors just not to process my request.
Since then after reviewing more and more info... It seems even if you are Zuckerberg yourself, you do not own your data... And even if you are a security service you can not guarantee/ensure your digital inputs. Since any tools you can use, they can use... And tools are created, daily.
For a little more info: (
https://www.zdnet.com/article/how-to-erase-your-digital-footprint-and-make-google-forget-you/)