Kebabs are still going well in Poland, but there are just too many Kebab places.
Kebabs are always going to be popular with the low end of the market, but as you say, there are too many of them. The point I'd like to make is that offering a good product or service is not enough, either in Poland or anywhere else. Over the years I have seen so many good restaurants close in Białystok. One of my favourites happened to be a really good Turkish place, which served almost authentic kebabs (they got round the difficulty of getting lamb by mixing mutton with veal, and it worked). Unfortunately, they just couldn't get enough people through the door, and they closed after less than a year. I'm sincerely hoping that the recently opened and excellent Elvisburger, just off Rynek Kościuszki, stays open. The only problem is that after the last time I was there I had "I forgot to remember to forget you" in my head for two days.