money can be exchanged for goods and services

Goods and services are not all there is in life.

Money can't be exchanged for lost time (e.g. due to making money), strained relationships (e.g. due to making money), dreams not followed (e.g. due to making money), etc.

So one has to strike a balance, and doing stuff as a hobby, without making anything money-wise, is a totally acceptable balance if you have your basic expenses (rent, food, etc) covered.

I'd count contributing to a retirement account a basic expense. The more money you make, the more you can contribute to your retirement account. Together with market returns it kind of makes sense to work a lot now to work very little in the future.

Again, it's a tradeoff against your dreams - if you work a lot now to work very little in the future, you may find yourself too old and weak in the future to finally do the things you always wanted to do.

OP wrote "financial security," not "enormous sums of money."

Yes, but OP also wondered why a random person will spend time studying and reporting stuff on his blog, if they don't make money out of it.

I didn't worry that he spent time studying. That is awesome! I worried that there was nothing about revenue. And I acknowledged that there may be more context (ex. the author is already independently wealthy, or the blog covers only non-commercial work).