If I'm making a quick soup for the evening; I'll use store-bought stock, if I'm making it for a huge group of friends, I'll put in the time to make my own.
Home made spaetzle is a great, quick noodle (and since I've got Celiac, it's an easy noodle to make GF) that takes about 5 minutes to actually make, 3 minutes to boil, and 5 minutes to brown on the stove top. Using it for Mac-and-Cheese is almost faster than the Kraft stuff.
And with anything that is a learned skill, cooking is slow at first; but as you get better at the basics it speeds up the process. As an example, it used to take me almost 2 hours to change my oil on my car; now I can do it as fast as a shop (~20-30 minutes).
The biggest thing that it all comes down to is time/money tradeoff, if I can convince myself that something is more worth the time it takes to do than the cost of someone else doing it, I can usually make it happen.
It's like anything else, you must invest the time and energy to get the quality. Restaurants simply abstract this away by increasing the cost.