I've been in the sauce business two full years now. Having done so, I've met a lot of folks as passionate about sauce as I. As a community you couldn't ask for a better bunch of people to hang out with at festivals. I've tasted all of their sauces, and they all fall into two neat categories: Sauces that taste best by themselves, and sauces that taste best with other foods. It really comes down to what your goal is for which you would choose, and the choice is as personal as any choice can be.
If your steak is dry and bland you add sauce to it to add moisture and cover up the blandness of the meat. Also handy when you burn the food. I think the most common examples of this style of sauce would be steak sauce, ketchup, mustard, and salad dressing. If you need to see the example in action, look to parents feeding young children. Kid won't eat salad, they put ranch on it and suddenly the kid is eating their carrots and broccoli. What goes on hotdogs? Mustard and or ketchup. My daughter would happily eat cardboard as long as she has plenty of ketchup to go on it.
Other sauces enhance existing flavors. NC barbecue sauces tend to enhance, they are generally thinner than ketchup so the excess sauce drips off of whatever you are putting it on. The thicker sauces like Kansas style or Texas style are thicker and sticker. You get more sauce on your food per bite and they act like a blanket over whatever you are eating.
Clearly, I'm biased towards the enhancement style sauces over the cover up sauces, but I really like the taste of food. When I go to a rib festival, I don't add sauce to the ribs I buy because I want to taste the meat, the smoke, and the flavor that was cooked into the meat. If it is bland, I'll enhance it with a little of my sauce to bring out the flavor that is hiding in their waiting to come out.
I'm not against the cover up style sauces, I do have a favorite one that isn't my sauce and I have no intention of ever trying to make one like it. I'd rather support a brother in arms and buy his food with his sauce on it and end up with his trade mark saucy face before I'm done eating.
To confuse things a bit, everyone has different taste. So a sauce that someone is going to buy again and again, someone else might not like at all, or they will like it but won't know how to use it. I've said, and heard said to me occasionally, "This is good, but what do you use it for?"
Some people have a refrigerator door filled with sauces, each sauce has a specific use and if that works for them wonderful. Others have a go to sauce that fits most of their needs, and they keep a couple of other sauces around for certain dishes. Some sauce companies create a lot of sauces for specific things (like Kraft salad dressings), other sauce companies create one sauce with the occasional small variant of the main product (think Texas Pete).
There is no wrong answer. You follow your taste and do what works for you, hopefully in doing so you are purchasing locally produced sauces by small businesses (like mine). Taste everything, buy what you like.