One of my colleagues told me that his salary is lower now than it was five years ago. Sadly, the price of goods is rising.
I do not believe this or the country that your friend is living is somehow not good at all. If the salary are lower than before, the price of goods supposed not to be increasing. What I noticed in almost all countries, as the price of goods and services are increasing, the salary also will increase in such a way that everything will balanced, but the government do the manipulation for their own good.
If you want to know if the global economy is declining, you will need to check the world gross domestic product. If it is higher in total than the previous years, that means the global economy has not declined in value.
You can compare 2021, 2022 and 2024 using the data on this link:
https://en.m.wikipedia.org/wiki/List_of_countries_by_GDP_(nominal). Click on list of countries by GDP (nominal), scroll down to table and click on it to see it.