You are arguing over semantics. GoT was a success. WoT is a "success". Are they the same success? When you change the bar for what passes for a success, many things are possible.
There are great success and there are mediocre successes. Even Warcraft film somehow managed to make enough money for Legendary to recoup almost all of what they spent. So there, WoT is a 'success'. It may remain "successful" for a season or two more. I don't believe it can grow, though. That is true success.