I used to keep a couple jars of store-bought marinara sauce in the pantry until I found that making my own version was pretty easy, cost effective, and most importantly allowed me to use a single batch of a “base” sauce then transform it in many different ways. Sure, I could always take the store-bought sauce and adjust ingredients or add some chunks of fresh tomatoes or diced and softened onions to make a more “rustic” texture, but I was still beholden to the base flavorings of a pre-packaged sauce. That led me to making my own basic sauce that starts pretty chunky and without many ingredients, but could then be turned into something very smooth if desired and modified with additional items. For example, if I were making a Detroit Style Pizza, I would use an immersion blender to make the sauce smooth. I would also add 1t each of red pepper flakes, and garlic powder, mixing well and simmering about 5 minutes.
For ultimate flexibility, the onions and oregano may be omitted. If I were making larger batches of this for canning or freezing, I would probably not use onions and oregano. Instead, when I opened or thawed a batch, I would cook what I wanted to add to it (e.g. onions), then add the sauce and additional herbs and spices, and cook a few minutes to warm it up. However, the amount of sauce this recipe makes is small enough that I can easily use it up within a week if there are any leftovers. It is also quick and easy to make, so there is no real advantage in my eyes to make larger batches for storage. That said, I am growing tomatoes in the garden this year, and that usually leads to a point in the summer where I am scrambling to figure out how to use up a large amount of them. If that turns out to be the case this year, I will probably look into ways to preserve this sauce for longer periods.
A full written recipe may be found here: https://cook.karylstein.com/g/family/r/base-marinara-sauce