I think the one-size-fits-all package idea is generally sub-par. There is always a problem of where you draw the line on what belongs in the package and what does not. In the time series context, what about state space models, bayesian analysis, bootstrap resampling, etc… All very frequently used alongside time series methods, yet also frequently used outside of it. I like that these are separate pieces.
A lot of the packages listed in the OP are probably not created with the intent of becoming “THE” time series analysis package in Julia. So the fact that they are perhaps hard to find is not an issue. I don’t mind if some guy’s replication files for his thesis don’t show up on page 1 of my search results for “julia time series”.
I would say one issue is that we do not have an easy way to signal the “quality” of the package. @Tamas_Papp has the right idea but as he says it is not easy. Maybe it could be made easier?