It all boils down to insatiable greed. The rich and big companies just care about is increasing their profit compared to last year [which is difficult to sustain] and grow their company. They will do budget cuts, fire due to redundancy, and cut corners just so they can do that. So while they get what they want, the regular employees suffer and are barely managing to live. So thinking about having a child is not even an option.

The immigrants aren't a solution to the birthrates. It never was. It was to supplement the dwindling workforce, and a way for the companies to increase their profits and cut costs [immigrants tend to get paid less because they are ok with the lower offer].