This quote from Wikipedia really sums it up. Note the attribution footnote for "some say"
In March 2017, Weather Underground stopped providing Doppler Weather radar Detected Storms on their NEXRAD page, and posted: "There are no Doppler radar detected storms for (any area) at this time." As well, lightning was never depicted on the radar screen, even when it was obviously occurring. When contacted[when?], IT customer service responded that the Doppler facility would be back soon, but the company was focusing on a smart phone app that gave the same Doppler Radar Detected Storms information. There was no mention of the lack of lightning data. However, weather radar data were still not available on the app as of May 19, 2018.
The Doppler Radar Detected Storms information was presented in a very useful format, because each storm was given an identifier that could be looked up by scrolling down to a grid giving more specific details: i.e. speed, direction of travel, intensity, hail potential, build-up tops, lateral size, etc. Many service users, including Emergency Weather Management Units, felt that was one of the most important features of Weather Underground, because it could be used as an early warning system alert for people in the path of inclement weather, and potentially minimize property damage.
Weather Underground seems to have slowly lost functionality and download speed; some say[who?] the service has become an afterthought since being purchased by The Weather Channel / IBM. Most loyal users, and customers contacted for this report, are hoping for a major format upgrade for PCs and laptops, to the previous format, and an increase in download speed.[citation needed]