The regulation of legal services in England and Wales pivots around reserved legal activities as defined by the Legal Services Act 2007 ("LSA"). These six rather narrow activities include some advocacy and litigation in a court (but not elsewhere), and drawing up of some but not all legal documents. Their scope and number arise not from a coherent analysis of risk and public protection but because the LSA simply re-enacted the pre-existing statutory provisions. These in turn were accidents of history as the seminal work by Professor Stephen Mayson demonstrates: https://stephenmayson.files.wordpress.com/2013/08/mayson-marley-2010-reserved-legal-activities-history-and-rationale.pdf

There is a huge amount of legal activity that is not regulated. The reserved legal activities are small islands in a wide stream.

Nonetheless many new alternative business structures are existing businesses that have chosen to become regulated even though they have perfectly viable businesses providing unregulated legal advice. Examples are quoted below. There are two possible explanations for this. The first is that the scope of the reserved legal activities is enough to ensure that legal businesses need to seek regulation to operate effectively. As Stephen Mayson shows that would be more by accident than design. The second alternative is that these businesses consider that they would be better off by being regulated as this provides an assurance to clients. The answer is probably a bit of both.