There are plenty of reasonable ways to build web applications. If the process you described works for you, that's great, but others do find different strategies

There are plenty of reasonable ways to build web applications. If the process you described works for you, that's great, but others do find different strategies effective too. For example, your process puts great emphasis on the visual design. To me, that aspect is almost entirely orthogonal to the software design. That's not to say it isn't important to getting a good end result, but once you know what interactions and information architecture you need, how you draw things on a screen doesn't affect anything else much. I suspect a lot of teams would start with the external models like interactions and information architecture, then move to internal models like database schemas or REST APIs, and then implement the former in terms of the latter.