Advanced users automate their installations
If you've spent any amount of time in the desktop linux community, you've almost certainly encountered the cliche of the "advanced user". Portrayed as an Arch or Gentoo user who prides themselves on doing everything manually, this figure plays a role as both a running joke and a symptom of a real underlying misconception about what it means to be a cut above.
But you will learn so much!
One of the primary arguments for manually installing and configuring your system is that it will teach you a lot about linux and operating systems in general. While there is a small grain of truth to this, it's incredibly misleading. Most of installing a system manually involves following a wiki or guide, and so the process of doing so only serves to refine one's reading comprehension and build a cursory knowledge of the tools used during the installation process. In the same amount of time, someone could invest into taking an operating systems course and learn deeply about the underlying systems in a way that manual installations cannot.
Computing is fundamentally about automation
A significant drawback of the "manual means advanced" slogan is that it creates a narrative that is precisely the opposite of the truth. Computing is about automation, and advanced users are those who write software or use existing software to make their computing lives more painless. A new user is one who repeats the same manual operation because they lack the expertise to automate that process. This is important because users, in particular those who go on to become software developers, carry forward this paradigm into their software and the broader software ecosystem.
Learn skills in the time you saved by automating
As I alluded to earlier, the best thing someone can do to build their knowledge in computing is to take courses in the subject matter. That isn't to say that hands-on experience is ineffective, on the contrary, it's probably the most critical experience. That's why any operating systems course worth its salt will be overwhelmingly hands-on. The difference is, instead of learning cursory information about high-level tools, you'll be learning how an operating system is written with help from instructors.