New Year’s Eve 2045 won’t be particularly festive for whoever’s left working at the Gates Foundation. That’s because Microsoft co-founder Bill Gates recently revealed that he intends to close the doors of his namesake philanthropic institution in 20 years’ time – after pumping 99 per cent of his remaining wealth into the charity. At the Gates Foundation headquarters in Seattle, the 70-year-old billionaire outlined how this swan song will allow the organisation to spend another $200bn (€117.5bn). The Foundation’s remaining two decades will focus on critical public health and development priorities such as maternal and childhood mortality, eradicating infectious diseases and reducing poverty rates through education and nutrition.

This second act for the former take-no-prisoners tech CEO is nothing but admirable. Derided in the 1990s as a monopolist and hauled before the judicial system in a landmark antitrust case, the Microsoft mastermind has rehabilitated his reputation for ruthlessness. For the past 25 years since starting the Foundation with his ex-wife Melinda French Gates, he has deployed his sharp analytical mind for something more important than selling software. It has made the bespectacled, grandfatherly figure into a kinder, gentler tech oligarch than the leather-jacketed Elon Musk and Jeff Bezos.

While a sunset clause has been part of the Foundation’s charter since its founding in 2000, a once abstract expiry date – several decades after the founders’ deaths – can now be circled on a calendar: 31 December 2045. No writer will argue that deadlines are useful motivators, but pre-emptively shutting the doors of the greatest philanthropic enterprise of the 21st century is shockingly shortsighted. Wealth of the scale that Gates commands creates the rare opportunity to build a lasting institution.

Countless readers have passed through the doors of the 2,509 libraries that 20th century Scottish-American steel magnate Andrew Carnegie built in more than half a dozen countries. Today, the Carnegie Corporation of New York continues to dole out grants to support education, democracy and peace with its $4.5bn (€4bn) endowment more than a century later. Indian industrialist Jamsetji Tata remains the world’s top philanthropist more than 120 years after his death – though Gates is likely to overtake him – as the Tata Trusts continue to have a profound effect on the livelihoods of rural Indians.

In justifying his decision, Gates argued that philanthropies in perpetuity risk straying from the founder’s intentions and spend conservatively to maintain their endowment. The Ford Foundation is a prime example of the former, a 50-year rift between the family and the foundation was only reconciled in December. But given Gates’s hands-on role and the Foundation’s eagle-eyed mission to focus on measurable impacts in global health and development, the Gates Foundation is better positioned than most to stay the course. Even as Gates whittles down most of his $108bn (€96bn) net worth in his final decades of life, it seems likely that stubborn infectious diseases will still be affecting life expectancies in sub-Saharan Africa. Recruiting top talent, including for a new Singapore office announced last week, might also prove challenging as 2045 draws closer. Who wants to steer an august institution into oblivion?

So, while the rest of the world is making optimistic champagne toasts to 2046, the Gates Foundation’s alumni will be left pouring one out in elegy. It doesn’t have to be this way.

Scruggs is Monocle’s Seattle correspondent.