Since the changes of IR35 this statement "Inside IR35" would mean you're controlled like an employee, and taxed so." is not really true. Only thing that matter

Since the changes of IR35 this statement "Inside IR35" would mean you're controlled like an employee, and taxed so." is not really true. Only thing that matters from the IR35 perspective is whether the service needs to be performed by a specific person in the business. All the rest is irrelevant. If the work is personal, then it is in scope. Risk averse companies can declare contract in scope by simply fettering substitution clauses or not having them at all. It doesn't matter if business providing service is legitimate or not.