Remember: once you retire, no one cares if you were a director. When you are 60, you are just old. The people that do care, you probably don't want to be friends with them.
I think she covered that by mentioning that architecture is more important as a senior developer. My understanding as a senior developer by what she means is not to focus on optimizing the hell out of code. Too often, people would demand others use the most optimize piece of code, but if the code is only going to be called once or twice, you should focus your time on other things more important.
I think your company is suffering from bad architecture design more than anything else. It seems like everything is tightly coupled with little room for modifications. This probably means those senior developers weren't really senior to begin with. This tends to happen at startups where business is prioritized and people get hired with inflated titles. I have seen that happen in a lot of startups.
I agree. Title doesn't matter. There is so much title inflation in the industry today.
For me, becoming a senior developer has allowed me to see code more objectively than before. Instead of following convention to the T, I can now look at code and make my own judgement whether to follow the convention. It's great to have the sense of relieve.