The phrase "have largely lost" is grammatically correct and can be used in written English to convey the idea that something has mostly disappeared or no longer exists.
Example: "Due to advancements in technology, traditional methods of communication have largely lost their popularity."
For one, it taps into a gap in the market: small and medium enterprises have largely lost out compared to consumers and large enterprises when it comes to tech innovations, particularly in the financial world — too specific in their business needs to use consumer services; too small to be able to afford services built for larger companies.
With Japan's industrial maturation, they have largely lost their focus.
College graduates are increasingly important economic drivers, particularly in cities that have largely lost their manufacturing sectors and the accessible jobs they provide.
The pronouns, which have largely lost masculine and feminine gender distinction, are quite different from those of Cushitic but nevertheless show affinities with Afro-Asiatic.
We have largely lost our faith in the validity of the human body as a symbol except in the context of eroticism.
In Europe, the remaining gypsies have largely lost what romance they had and are mostly regarded as a nuisance.American hobos, though, are associated with two powerful sources of myth: freight trains and cowboys.
But by and large, the meaning of the day has largely lost its significance among the public, becoming simply about getting the day off work.
By the turn of the century, it had largely lost its capacity to enforce Pax Britannica.
Psychiatry, as a discipline, has largely lost interest in the content of delusions.
The new prime minister inherits a government that has largely lost the confidence of the Japanese people.
In this policy area, as in others, the American political system has largely lost the capacity to learn and react.
