Obviously, there's plenty of bias here given the source, but I think on balance it either hinted at or laid out a lot of the issues we know about the state of 9-5 employment, most notably in the U.S, fairly well:
-Lack of control over schedule/location
-Lack of growth paths at many companies
-Lack of leverage/Inputs match outputs almost 1:1 (sell time, make a dollar)
-Not getting rewarded for the value you bring to a job; instead that value accruing mostly to people above you
-That feeling of being merely a line on a spreadsheet
Over time, I've learned that for some people, articles like this will really resonate and shake them to their core. (I happen to be in that category but I've experienced enough in previous entrepreneurial ventures for this enthusiasm to be tempered a little bit with reality every time I read things like this).
Others will recoil seeing this, their first instinct going to the (very real) risks in leaving that system and conclude they're far more comfortable optimizing for the familiar.
Both reactions are perfectly OK. There's no wrong or right answer. It's just what connects with you, as a person.
The key is to understand that, either way, you're in charge of your career, regardless of what kind of professional setup suits you best and makes you happiest.
As others have said, this strikes me as a multi-faceted problem.
It's possible Google devalues those sharing (even inadvertently!) GA tags in the rankings, although I don't think there's been any public proclamations from Google on that. But if that were the sole culprit, only your GA instance would reflect that. The fact that you're losing real traffic (as reflected in what the 3rd party tools are telling you) makes me think that's probably not the case/or at least the only thing that's happening.
Not implementing re-directs would also definitely be a culprit. But if it's just images you failed to re-direct, that's likely not the main thing either unless you were getting a majority of your traffic from Google Images.
Since this happened post-Core Update, I would want to know two things:
1. What keywords dropped and what replaced you
2. Whether the drop was site-wide or isolated to individual categories or groups of pages.
Regarding #1: Was what replaced you a big, high authority publisher? Or was the content simply more comprehensive or otherwise a better match for the user's intent? Very likely could be E-E-A-T-related, in terms of the algos determining that you don't have the authority/expertise to rank for what you were ranking for previously.
Investigate those possibilities first and you should be able to better map out a plan for re-gaining that traffic.
-Lack of control over schedule/location
-Lack of growth paths at many companies
-Lack of leverage/Inputs match outputs almost 1:1 (sell time, make a dollar)
-Not getting rewarded for the value you bring to a job; instead that value accruing mostly to people above you
-That feeling of being merely a line on a spreadsheet
Over time, I've learned that for some people, articles like this will really resonate and shake them to their core. (I happen to be in that category but I've experienced enough in previous entrepreneurial ventures for this enthusiasm to be tempered a little bit with reality every time I read things like this).
Others will recoil seeing this, their first instinct going to the (very real) risks in leaving that system and conclude they're far more comfortable optimizing for the familiar.
Both reactions are perfectly OK. There's no wrong or right answer. It's just what connects with you, as a person.
The key is to understand that, either way, you're in charge of your career, regardless of what kind of professional setup suits you best and makes you happiest.