How much work is it to create a simple ERC20 DApp?

As somebody who's been following crypto for a while, I'm genuinely curious to know how complicated is it for somebody to build a live crypto project? Some of the Githubs I've seen for projects with big valuations look like about 100 lines of code and barely a few devs. I'm only a hobby Python programmer so I'm not hugely experienced with development, but if for a fun experiment I wanted to create a simple Ethereum DApp with its own token, how long would it take to learn how to do that?