Some of the big news agencies and state media do send in war correspondents. However, investigative journalism has almost disappeared, not only for war stories, for financial reasons. Therefore, there is a reliance on second hand reporting and some media outlets are less vigilant about checking their sources.
Yesterday, the BBC was nearly half an hour behind other media on reporting the killing in Milan of the Berlin truck murderer. I wondered why. At first, I thought the BBC was asleep on the job, but then realised that other outlets were reporting unconfirmed sources. The BBC waited for the official announcement by the Italian authorities, which is why I would still trust rather than outfits such as Sky, which almost exclusively uses secondary reporting.
Many years ago, I worked for Reuters and we monitored how quickly we got out our big news stories and were always in competition with the other news agencies, so half an hour would have been frowned upon. However, we also used to monitor the source of the information and who confirmed stories. An official source could not be compared with 'Fred Bloggs said...'.
These days, the internet has completely changed the situation. News outlets rely on 'live' pictures from outsiders. These can be manipulated to show just one side of a story. Undoubtedly some pictures from the Middle East do just that. Moreover, some governments use doctored photos for their own propaganda and have sometimes been caught out using archived pictures from historic conflicts. This is what Farage did with his immigrant poster. He used a genuine photo, but accompanied it with an entirely different narrative.