The second round will collect 2 times less votes, and maybe less. This competition has already been going on for more than a month and a half and has not yet been completed. And with the second round, how long do you plan to hold it? For 2-3 months?
Current contest took so long due to the war context from Ukraine, which prevented icopress from counting the votes faster, from stopping the voting process earlier, from creating the BB code for announcing the winners, from talking to other people involved in the organization of the contest etc. (by "etc." I mean everything which is contest related -- these being activities which take a lot of time; and by "a lot of time" I mean dozens of hours). When a war is on course in your country, nothing is more important (including a contest on a forum) than keeping your family safe. Besides, how many would think about a contest organized by them on a forum, when they and their families' lives are in danger at any second?! I highly doubt that many would think anymore about finishing other activities initiated before their lives started to be threatened -- literally speaking -- at any second. Still, icopress did not abandon this contest and he is still trying, during the few spare time he has, to take it to finish line -- and this is admirable!
In my opinion, even if he would finish this contest in December 2022, this should be understandable, if the war would not end by then. In the context that you fall asleep but you don't know if you are still alive tomorrow, everything else excepting the attempt to keep yourself and your close ones alive is a minor thing... Bluntly speaking, how many have ever lived a situation like this? How many actually know the feeling of not knowing if tomorrow they will be able to open their eyes anymore?
However, coming back, in normal conditions, if such a contest would be kept for 2 weeks -- let's say, continued with a play-off phase, which would be kept also for 2 weeks, then the entire contest would take about a month. I don't see any reason why it would become more boring. A football championship lasts for one year and nobody gets bored to see the games. Besides, an eliminatory phase followed by a final phase represent a manner to bring more interest for many international competitions.
Besides, as yahoo said, this contest (together with other contests which took course within the forum) is meant for fun. There should be no rush to reach the finish very fast, as this will only make the fun last less.