Road riders need lightweight, tiny tools that can fit into jersey pockets. A lot of those items are made of carbon fiber, which is lighter than aluminum. Other iconic trappings of road riding, like CO2 cartridges and spandex outfits, are also geared toward minimalism, but all of that downsizing comes at a cost. Commuters don’t have to be as concerned with weight, so unless you covet something specific, don’t spend the extra money.
If you’re going to use the chain whip you just made, you’ll also need a way to get that cassette off. A lockring remover is a must-have; unless you use one of the shady removal methods I’ve seen on the internet—which I wouldn’t necessarily recommend unless you don’t care much about the condition of the wheel after you use them. I recommend Park Tool’s iterations here that cost about $6, but you’ll need to buy the specific one for your brand/type of cassette. (By the way, I’m assuming you already have an adjustable wrench laying around somewhere to use with this tool. If you don’t, well, you’ll need one of those too.)
A multitool is a highly versatile piece of repair equipment that can address most of your maintenance needs. Ideally, you should use it before a ride to tighten and adjust everything properly, but sometimes it’s necessary on a ride as well. If you encounter a loose screw, realize your saddle height is not right, or that your brakes need tightening, you will be happy to have it.