You don't have to constantly keep upgrading. Not sure where you got that information from. You don't have to keep upgrading, just as long as you don't buy too weak of a PC.
You don't have to be tech savvy, but if you want to make the most of it, I'd highly recommend learning about PC specs and the requirements that your games have.
With that being said, PC gaming isn't always as straightforward as on a console, I'll admit. You have to deal with Windows updates, which may or may not mess things up. Game updates/patches are common, as with consoles. Popular games tend to have modders online which also get annoying.