Especially mid to late game, buying those is trivial both in terms of resources and in terms of how useful the bow and arrows are. Unless something has dramatically changed since I last played, Archer kit just gives you arrows and has a useless block breaking feature. Builder is a legitimately good kit because blocks are useful early game, and so are the platforms. Archer? Buying a bow while people are still bridging is rarely a good investment. Bowspamming is economical if you're not buying the arrows I suppose, but you don't get arrows fast enough to actually do that much. Archer is not overpowered.