It loses flexibility and readability for others, but you don't usually have enough time to concern yourself with such flexibility if you're working on a project by yourself, and you're not concerned about onboarding other developers and having them understand your code. The upshot is then that as a single person "bad code" is often highly effective code, and "clean code" is expensive code that buys you a lot of stuff you don't need or want.
I say this as a boring enterprise developer who at work is highly concerned with appropriate abstractions etc. imo there's no universally good approach, what is optimal is context dependent. Although there are some core features of code like consistency and strong conventions which are fairly universally helpful, this represents a small fraction of best practices.