To be sure, I could never do the job that you do. Thanks for what you do.
As far as the article you posted a link to, it's pretty good advice but it never mentions the word "code". That's a short coming I see for many DBAs. They can survive with monitoring tools and dashboards but I find that the really good DBAs know how to write T-SQL for special things and even daily work even if you're "just" a system dba.
If you're an "application" DBA or a "hybrid" (system and application), you really, really need to learn some of the finer art (and, sometimes, the "Black Arts") of coding in SQL. You also need to be willing to teach it to Developers and other DBAs, as well. A lot of "bad" code that eats the face off your servers can be avoided by showing people how to code.
To wit, I've found dashboards are nice and all but they don't quite do the trick for me when it comes to certain important stuff. For example, I not only want to know things like what ran/failed/was cancelled last night but I want counts, averages, and need to know things like was a job changed and who did it, etc, etc. So I need to see everything about jobs including what ran successfully. With that, I wrote a ditty that sends me a formatted email for the relatively small numbers of servers that I have. If I was line-tending 10's or even hundreds of servers, I'd do roughly the same but only report the failures and changes and missing servers and the like.
Sounds like a monitoring system but it's not. It's all in morning reports and I don't have to remember to "save" a copy for audits, etc. It's a part of the email history. That also allows me to delete job history from MSDB, which can grow by leaps and bounds when you have a whole lot of "per minute" jobs.
You can certainly survive with purchased monitors but every company is different. If you have "special" things you want to do, you're going to have to know how to write some decent code to do it or at least know how to read someone else's code and modify it without it becoming a "usage issue" as well.
If you're an "Application" or "Hybrid" DBA, you really need to learn how to code so when the Developers say "there's no way to make it faster or less resource intensive) when you present them with a problem, you can use that to make a "Mentor Moment" that can have a huge impact on the success of the company.