@spider109 You need to remember that CT scans were new, rare, and very expensive 30 years ago. Many smaller hospitals didn't even have them - you were sent to a larger medical center for imaging. So physicians worked with the tools they had.
My Mom had lung issues, most probably Bronchiectasis for 30 years or more before she died in 2011, but it was only diagnosed about 5 years prior to her death, during a heart CT that took the cardiologist about 6 months of appeals to get approved.
I attribute the recent increase in diagnosed cases, especially asymptomatic ones, to the "preventive" screening many former smokers are getting for lung cancer, and the much wider use of CT scans in general. This is great because BE is diagnosed in early stages - if people continue to monitor, and if needed, to make adjustments like doing airway clearance if their condition progresses.