'essentially obsolete' is a correct and usable phrase in written English.
It is used to describe something which is no longer widely used, and is near the point of obsolescence, but is still being used to some degree. For example: "This technology is essentially obsolete, as newer and better alternatives have since become available."
By the time the airport opened, in 1975, it was essentially obsolete.
Since 1984, Harley-Davidson has sold hundreds of thousands of essentially obsolete motorcycles a year, at a premium price to faster, smoother Japanese machines.
His path to peace is based on the degree to which social change and the resolution of conflict can be achieved by an embrace of nonviolent tactics and ideas, combined with his assessment that a combination of nuclear weaponry and "people's war" has rendered war essentially obsolete as a rational political instrument.
Getting a business prospect to answer their phone seems almost impossible, hence making the "art of cold calling" essentially obsolete.
An argument about government regulation of tech is often that it is both heavy-handed and so slow that by the time it finally happens it applies to the tech of several years ago and is already essentially obsolete.
And with that, the Lower 48 segment of the Alaska Pipeline Project has become essentially obsolete.
3D games will see a similar improvement in quality, and this level of resolution essentially obsoletes antialiasing filters.
To essentially render private cars obsolete.
Up until the announcement of the iPad, writes Auletta, Amazon was going to begin their own imprint, essentially making hardcover books obsolete and then cutting out the publishers and going right for the authors.
This one offers a screen that turns into a mirror, essentially making the pocket compact obsolete.
That's 45 million devices in essentially perfect working order that will be partially obsoleted by this move.
