On the contrary. It relies on the premise of segregating binaries, config and data. But since it is only running one app, then it is a bare minimum version of it. Most containers systems include elements that also deduplicate common required binaries. So, the containers are usually very small and efficient. While a traditional system’s libraries could balloon to dozens of gigabytes, pieces of which are only used at a time by different software. Containers can be made headless and barebones very easily. Cutting the fat, and leaving only the most essential libraries. Fitting in very tiny and underpowered hardware applications without losing functionality or performance.
Don’t be afraid of it, it’s like Lego but for software.
Beware, Gnucash is meant to be pro level accounting software. Is not a simple ledger or a tech/crypto gateway. I also use it for my personal life, but there’s like 30% of features I don’t use because they’re business accounting stuff I don’t need. It predates the cloud, it cares not for the latest trends, it crunches numbers and spits out reports. That’s part of what I like about it. It is not simple but it also isn’t bloated.