To add to George's legal answer, I'll discuss the practicality of using this method to create a legal "copy" of the font.
Tracing by hand isn't required, but at some point I would think the vector outlines would need to be rasterized (at high resolution mind you) to be legal. Yes, there are programs that could auto-trace the outlines for you but they're far from perfect. Proper well-designed fonts have outlines that usually have points at extrema to be more efficiently rasterized. A generic vector trace program may not generate curves that meet those requirements. However, font creation software usually offers tools to optimize curves in that manner.
That said, fonts are more than just outlines. Each glyph in a font has a bounding box within which the outlines sit. For example, the letter H may have an outline width of 500 units but a bounding box width of 600 units with, say, 45 units of padding on the left side and 55 units on the right side. Each letter is different, so you'd need to print each letter out with a bounding box as well as the x-height, capital heightline, baseline, ascender lines, descender lines, etc. Flat letters like L, H, I, etc. will have a shorter height than round letters like C, O, Q etc. This is called overshoot.
Once you have the glyphs placed in their proper bounding box, with the right amount of spacing on both the left and right side, if you have a monospaced font, you're done (save hinting, mentioned below). If, however, you have a proportional (variable glyph-width font) like Helvetica, Arial, etc., your fun has just started. That's because letters like A and V need less spacing between them because they naturally fit together: AV as opposed to something like AH. Similarly, the
o in the word 'To' needs less space on the left because it naturally can be tucked underneath the T. These slight adjustments are called kerning, and fonts will have a set of kern pairs for all the glyphs that need adjustment. There can be hundreds to thousands of kern pairs in a font. These values are saved in the font and available to see if you open the font in font creation software. However, there is no easy way to measure this (like you could for where the glyph sits in its bounding box) that I know of. So, is it legal to look at the font you're "copying", see that 'AV' needs a kerning value of -60 units and plop that into your new font? I don't know, but that would seem like copying to me, which could be a violation. You could do it by eye but that takes skill and lots of time. I've created a couple fonts for personal use and it can be a daunting task. Granted, I'm a perfectionist, so it's possible that what's "unacceptable" to me might be more than acceptable to someone else.
Fonts also have instructions called hinting which help make them more legible at low screen resolutions. This mostly affects only how the fonts look on the screen; they'll print out just fine. While hinting was very important in the days of CRTs and 72dpi screens, it's becoming less and less important as the resolution of screens gets higher and higher. As far as I know, at least for macOS, hinting is no longer used for screen layout of fonts. I'm not sure about Windows or other OSs.