Maybe if your electricity is free or cheap mining is still worth, but if your electricity cost is expensive is not worth. Remember, a lot of peoples mining and it makes coins difficultly increased and the market condition is not supported now.
You are right. The mining market is very mature now, there are plenty of companies running their mining farms all over the world. The key factors are electricty price and calculate power(equipment).
Agree with that. One can keep mining if electricity costs lower then mining return. But buying any new equipment is not a good idea now and may be it's not a time to consider mining as a busines. It is fun that can provide a free pizza. Something like this.