Why File.ReadLines() in C# allocates too much memory?

I have twenty 10MB txt files and would like to read these files.

I have read this, which says File.ReadLines() doesn't load entire lines so it doesn't spend much memory.

var directory = "path/to/files";

foreach (var filepath in Directory.EnumerateFiles(directory, "*.txt"))
{
    foreach (var line in File.ReadLines(filepath))
    {
        // I will do something here, but not yet.
    }
}

But when I run this code, Jetbrains Rider DPA says like below image.

How can I fix this problem?

Environment: .NET Core Console Application (6.0)

Edit

Same problem with StreamReader.