In the UK at least, you would need to be careful that by allowing people to waste your time (and them paying for it) you would be breaking the dreaded IR35 tax rules by appearing as a “disguised employee”.
HMRC won’t tell you the exact rules but one of big tests is do you retain control of your time or not.
You need to be upfront with clients about what they are paying for or you could both be in for a nasty surprise.
https://www.gov.uk/government/publications/off-payroll-worki...
Along with a handy tool at https://www.gov.uk/guidance/check-employment-status-for-tax
I used to get contracts checked to see if they were Outside IR-35 and I knew I wasn't the only one. So it isn't straight-forward as you suggest.
It can also scare companies off, I have personally experienced this. As a result there are far less Outside IR-35 work. Almost every contractor I know has had to go back perm.
I understand there were many Contractors that basically milked forever contracts, but it kinda screwed over loads of freelancers.
I personally hate being perm. I used to work about 6-9 months a year and I found it relatively easy to find another contract. I had plenty of free time. Now I get the standard 1 month and bank holidays. Really pissed off about the rule changes.
Just the fact that they issued him a laptop and specific software would tend to indicate that he's an employee not a contractor.