system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why aren't blimps all that popular anymore?
gpt
You need a massive massive building to park/service a blimp.
They go much much slower than a plane.    
For all those problems, it still couldn't carry much more than a plane.(especially if you opted for non-flammable helium, rather than flammable hydrogen)  
  
Now there are some niche purposes, like the ability to stay in the air for a very long time, but for taking stuff from point a to point b, planes were usually just better.