When one looks to build anything in the physical world, one must build up. By nature of having a physical representation of what one works on, one can plan as one goes. However, even then, differences in craftsmanship exist. One who plans out each brick and has done so for a while will know how to do it more quickly than someone who has not done so. This expertise compounds with every iteration, where the individual taking care to lay bricks expertly gets better at them.
The flip side involves a focus on getting the job done and nothing else. There is no care as to how, only care as to meet the requirements. Whether this approach is right or wrong is not the point; the point is that, seemingly, despite both building a house, one gets better at building a house while the other gets better at getting the job done.
There is wide middle ground between these two, but I tend to lean towards the getting the job done side. After years of doing this, I feel that I have gained medium levels of exposure to many things, but am lacking deep exposure to one thing.
Again, there is no right or wrong approach, but the transition to one from the other needs an articulation of what one is transitioning to. So for me, if I am used to getting the job done to develop medium levels of understanding, this continued approach does not translate to deeper understanding in any topic. If deeper understanding is the goal, then a focus on fundamentals should be as well.
I suspect that the harder thing to stomach is the longer time to see results. There are fewer markers as to whether the time spent is worth it, and less time spent being able to “optimize” a solution. Optimization is necessarily in quotes, because there is no guarantee that you actually optimize anything without before and after metrics.
One thing I always like to turn back to, is how with the products Jony Ive worked on for Apple he focused on what the internal components looked like as well as the external design. To me, this was a key aspect in the general attitude to Apple products, and is a north star to strive towards when focusing on the basics.