Laws and case-law are always changing, but whatever lawyers do to stay current seems to work well enough. Building codes change, but certifications for electri

Laws and case-law are always changing, but whatever lawyers do to stay current seems to work well enough. Building codes change, but certifications for electricians/plumbers/whatever seem to work well enough. The certifications I've heard of all come with an expiration date. The professional organizations I've heard of all require at least a little bit of ongoing study from their members. I don't see why what works well enough everywhere else wouldn't work well enough here?