Yeah same here. I was asking the same thing and the tower just randomly pop-up without any reason. The characters are easily accept their new normal without asking why or whatever.. I felt like I'm reading 5 or more stories in one.. idk.
He's not an otaku. Read the first chapters again. He's someone who played a game for 7 years but he was not cope up on his room. He makes mukbang videos even and was stated on a chapter he needs to cancel his gym member for he's short in money. He is a vlogger not some kind of weak hikikimori.
To add to the persons comment above it wouldn’t be that he just suddenly got strong but he had a huge upper hand compared to everyone else since he would know all the secrets and unique abilities/paths he can take to increase his abilities that fast. So if you consider all of this it makes sense that he would get that strong that fast.
If he had done the opposite and took forever I’m sure you would say “he knew all those secrets but still can’t even do anything”
And there’s no middle ground that works in this scenario because it would be the same as if you went twenty years back in time with all your current knowledge and then Just ignored all of your past knowledge to influence your current life. It would be basically the same concept. Of course you would become someone significant fairly quickly
this is lowkey cringe cause how did he go from being an otaku and having no physical ability on the first chapter to sprinting and killing on the second like wtf