I didn't downvote you because I understand where you're coming from. The APIs you work with probably don't change and you already know most of them, disabling code completion works for you. But if someone renames things in your API, you'll be slower without completion. And if you're working with a new language/framework (or even just a large library), you'll reaaalllyyyy wish you had code completion.
A few years ago, I started working on a project where I needed to use C#. I'd never written a line of C# in my life, so I installed VS and with the aide of Intellisense, I went from having a "Hello World" snippet from Google to using several C# libraries to create a ~1000 line PoC in a day. A few days later, it was production ready. Without Intellisense, this story would be very different.
A few years ago, I started working on a project where I needed to use C#. I'd never written a line of C# in my life, so I installed VS and with the aide of Intellisense, I went from having a "Hello World" snippet from Google to using several C# libraries to create a ~1000 line PoC in a day. A few days later, it was production ready. Without Intellisense, this story would be very different.