steve voigt
Lots of things are not necessary, but make work easier or faster or more enjoyable. I don't own a fishtail, but I don't cut a lot of DT's. If i did, I'd grind a fishtail.

There's a good argument for restricting oneself to necessary tools. As Warren often points out, it breeds familiarity with ones tools if the kit is of manageable size. It's also cheaper and takes up less space.

On the other hand, having a few "nice but not essential" tools can definitely help. When deciding whether to acquire such a tool, it's good to weigh the cost and space against the utility of the tool. For example, a dedicated iron shooting plane and vintage Stanley shooting board would cost a small fortune, weigh a ton, and take up a lot of space. It's hard for me to imagine it being worth it. On the other hand, to make a fishtail chisel, it would cost less than $20 for a vintage chisel that I could re-grind in an hour. What's not to like?