In a country that had and still does have corruption, he probably knows what is going on. Also, while we are on this subject, according to the Ukrainian constitution, when martial law is in place or war is going on, they are prohibited from holding elections. So in effect, they are trying violate Ukraine's constitution. Even the opponent of Zelensky, the previous president Petro Poroshenko, knows that elections can't be held. It's been that way since 2015. Also, it would be a huge risk to do elections and campaigning in a country at war, especially with an aggressor country that wants to wipe Ukraine off the map. So by doing elections, that's putting millions of people at risk. Also, forget about Zelenskyy for a second, why hasn't anyone asked the average Ukrainian what they want?
Let's not kid ourselves, Zelenskyy is in a very difficult position, and not just from outside, but politically within. He is from Jewish parents. There are ultra-far right groups in Ukraine, such as Svoboda, Right Sector, National Corps, and others. Many of them are Banderites, followers who see Stepan Bandera as a hero. In case you don't know who he is, he was a Ukrainian nationalist who was part of the OUN, the Organization of Ukrainian Nationalists. He is a controversial figure. Many see him as a liberator and martyred figure, while others say he was a fascist and Nazi collaborator whose followers killed Polish and Jewish people in WWII. Ukrainian nationalism is especially prevalent in western Ukraine in places such as Lviv, Lutsk, Khmelnytskyi, Ivano-Frankivsk, Zhytomyr, Rivne, and Ternopil. Keep in mind, he wasn't popular when the invasion started. So he's got a lot of pressure just in Ukraine itself, never mind from outside.