Not only this is important, but another huge consequence/advantage of following best practices (either for architecture or smaller patterns) is related to the technical debt.
The more you follow best practices, the easier it is for a dew engineer onboarding the project to get it, understand how the pieces are articulated together, to look for a component where it logically should be, in short, to feel at home quick. From an engineering point of view, it enables the engineer to focus on what matter rather than digging in uncommon stuff, and becomes frustrated. As a bonus, being able to focus on the relevant stuff rather that trying to get how it has been built is less frustrating, which translate to a more productive developer... and in the long term, the engineer is less likely to quit and try to find a better project elsewhere.
From a business point of view, following software engineering best practices helps managing the velocity of the project. The less technical debt you have, thanks to these best practices, the more constant your feature development stays, and the more predictable your schedule can be.
This is a really short addition on the reasons why you should follow software architecture best practices, there's lots of conferences on the subject that are more educated that this small post ;-)
Séb