Following the nightmare that was 2020, and the losses of jobs which happened, this may seem like an odd statement. A lot of people are suffered and struggled as a result of losing jobs. Others are very thankful they kept theirs. It may, therefore, come in bad taste to say that you should be keeping an eye on the job market. Especially when a lot of people are fully immersed in it to keep a roof over their heads, or food on their tables.
This isn't a post about pushing for a raise during touch economic times. Nor is it about encouraging people to leave a stable job for something which might be unstable or risky.
That said, one of the reasons to keep an eye on the job market is to make sure you are paid at least the market rate for your role. That may drive some resentment to your current employer if you are (or feel) underpaid. But it may help drive negotiations at any performance review or appraisal to help get you what you are worth.
Similarly with new architectural models and languages which support them. The last half-decade has seen a big push to microservice architecture, and a mix of languages. This allows companies to pick the right tool(s) for the job. A lot of those (from what I have seen) appear to be written in Go, a language which seemingly appeared out of nowhere.
Some of these things may be a passing phase and be replaced again in a couple of years. But, if you are able to get involved in some of them, you can add projects to your portfolio which demonstrate your ability to learn. They can demonstrate your ability to adapt. They can also help develop different thought processes for solving various problems.
All of those benefits can lead to new doors opening up in the future. New roles. More senior or decision making roles, should you want that. The benefits of career progression and the economic boos that may bring to you (yes, it usually comes back round to money), are something which a lot of individuals want.
There you have it. Keeping an eye on the job market doesn't mean you need to be open to applying for jobs. See what is out there, what skills they need, and see how you can utilise that information to carve out the career path you want. Hopefully you can help build your way to financial independence at the same time.