Ali Abdaal did a good video about how much money he made in 2020 (he has 2 million subscribers) and he made £100k from Adsense, £132k from affiliates, and £136k from sponsorships. Most of his content is about tech/finance who earns considerably more adsense/sponsorship money than fashion/beauty, so he earnt £360k in a year with much more subscribers.
If S&C write off most of their hotel stays, holidays and transport etc as business expenses, then the only thing they spend most of their money on is bags and clothes, which also get a business tax relief because it's for their job. They also don't have any friends and most of their stuff is gifted, then they sell the majority of their gifted stuff on Depop so I feel like it wouldn't be hard to afford a couple of £1000 designer bags a month tbh even if they were on something like £100k a year (which I think is less than they are on)...