I was just about to ask about their background as both sides of their families seem incredibly well off - Not everyones Grandparents can buy them holidays abroad to USA! And what did Joel do for work before Youtube? I doubt it paid him that well that he could buy a property that big in Surrey of all places along with two fairly expensive cars - they live a very comfortable life so I did some digging as it wasn't adding up.
I found that they have a company with all their YT income (I'm guessing) and currently have excess of 85k in the bank just from Youtube earnings IN 2019 ALONE. The company was only set up last year I think and they can claim all the stuff back on their taxes that they use in videos such as prices, shopping videos etc. I also found their address from here (which is very easy to do and is public info but I won't be sharing how I did so) - The house they live in was purchased in 1996 so I'm guessing its owned by one of their parents who has given it to them which is absolutely crazy as that house now is worth over 1 million POUNDS! The house directly next door to there's was sold last year for over a million as were houses on their street. They clearly had the financial backing from their parents and privilege of their upbringing to enable them to quit their jobs for YouTube and most likely an inheritance to fall back on.
Going back to the company, they haven't listed any employees but make it obvious that Roland helps them a lot and they must pay him along with buying him that car. I don't think they pay him much tbh, probably as and when he prepares ideas and videos, by the hour as a second income off the table for Roland.
Did some more digging and wow did not expect Joel's parents company to be what it is!
If they didn't mention Joel and his siblings name in this article, I honestly would not believe they were his parents! I double checked on companies house too and the its definitely them. No wonder they keep them both off camera unlike Sarahs mum - very interesting.
https://www.theguardian.com/media/2007/mar/02/broadcasting.religion