I am not sure there is a single solution to this that would work across all industries, as the impact of the bus factor can be quite different depending on the business.
Software as a service requires that someone else has access to servers, repos, and the required technical expertise to keep it running. An accounting business or lawyer would require a roadmap to transition all their files and documents.
Maybe the generalized solution is like ISO 9000 or XBRL for transition planning along with a centralized depository with all the information required for a transition. The depository releases the plan upon the receipt of a death certificate or a board motion or just a lack of contact with the founder over a certain period.
I don't know if insurers are permitted to package coverage separately like this. They heavily abused it prior to Obamacare and a lot of the regulation in Obamacare mandated that any insurance plan cover a certain set of procedures and medications. The largest barrier seems to be regulatory.
MindSumo.com (business, writing, marketing, research) is somewhat like this as is Eyeka (for design) and they both tried the job angle much more heavily in the past in the past. The problem was that companies never bought into the concept so they had to pivot heavily.
One of the big problems is that for every undiscovered gem, 100 people who enter are absurdly unskilled. MindSumo entries were all public at one point for portfolio creation and the quality of most of them was terrible. You could easily spend hours reading entries without finding ones that were even of passable quality. You will absolutely get a couple of stellar entries out of a MindSumo challenge, but you have to find them from among the rubbish.
The other challenge is that the successful people on the sites are also conventionally successful people. Examine the leaderboard and you find a group of people with many other accomplishments to their names who can get past traditional resume screening. MindSumo has not proven that a wide pool of candidates with otherwise weak on-paper backgrounds exists. It is another feather in the cap of people with already strong backgrounds.