In order to hack & hew, wack & pound, shave & scrape, chop & pare, you need things to hold the piece you're working on. There are a multitude of dogs, hold downs and clamps you can buy. But you can make many of them with scraps laying around the shop. Slip and hit a metal dog with a chisel or plane iron and it's going to cost you a half an hour or more to repair the damage to the cutting edge of your tool. If the dog is wood, well you'll have to slip a lot before you damage a wooden dog enough to require replacing it. A wooden peg to support a long board you're planing won't transfer rust, oil, DW-40 or paint to your board. It isn't likely to bruise a sharp edge if you're a little careless and drop it on a wooden peg or screw.
With the proper accoutrements a workbench becomes a versatile multi-directional clamp and a platform for various jigs and fixtures - bench hook, shooting board, miter gauge etc..
Plenty of small projects to fill in between larger projects. Here's and idea I borrowed from Ken Vaughn's bench. Here's one of his ideas - an auxilliary vise. Here's a link to Mr/ Vaughn's version My Bench Index has a link to his workbench page - well worth exploring if you want to get the maximum out of the bench you build.