Being self-employed is quite good when you are earning bundles of money. Then you can budget for the fact of no sick pay, pension, job security or holiday pay, and you can handle the expenses of buying and maintaining your own vehicle. However, courier companies have the consistent habit of recruiting too many riders thereby diluting everybody’s wages no matter how good or fast you are. Courier companies appear to have zero loyalty towards the workers from this point of view.
Ninety-nine percent of us work for one courier company at a time, maybe for a few days if it's really shit, but usually people stay at a firm they like for several years. The courier companies decide the rate of pay and most other conditions of work. This is not true self-employment as defined by the Inland Revenue, no mater what your boss says.
On the face of it the courier companies have all the advantages of a self-employed workforce with no benefits to pay out for, no responsibilities towards our welfare and no expenses for maintaining a large fleet of high-mileage vehicles. On the other hand the bosses also have the advantages of treating us like the normal employed wage-slave, i.e. being told what to do and when. Despatch riders and cycle couriers are getting the worst of both worlds. This might explain why some people refer to self-employment as self-exploitation.