Employees have to temporarily take on extra work while managers promise that the open headcount for the senior dev who just left will be filled as quickly as possible. In fact, you should refer your friends! (who will all be promptly rejected)

You can tell your staff that you're trying to hire more people but it's hard, and if they can just put in the extra effort now it'll be easier in the future. Meanwhile, you get to save paying for an extra person and get more from your staff, so profits go up.

For one it lets them lobby to cut unemployment benefits and to incidentally cut taxes, which many business also lobby to avoid.

It’s a free rider problem of profitable corporations on labor of society.

Employers keep doors open for really stellar candidates - they keep interviewing - and if such a candidate comes, a position can be created, with overall goal of improving quality of employees. However the pool of extraordinary candidates is shallow, so the stable state is "positions are supposedly opened - interviewing happens - nobody get hired", with rare exceptions. This skews the statistics - everybody reports "hiring and can't find (exceptional) candidates", but workers in fact can't find a job for a long time.

It's not whining, it's a strategy, when interviewing costs relatively little. Even startups spend weeks of interviewing for a single candidate, because prevailing opinion is that it's more costly to hire a subpar employee than to do those interview rounds, even in a jurisdiction where laws allow firing with relative ease.

Believe it or not, this has become a political issue where conservative media is trying to spin this as people being too lazy to work, or welfare being too good. This is being called "the war on work" by conservative media [0]. The goal is to get popular support to weaken an already laughable welfare situation in the US so that workers have no choice but to go to work at terrible wages/benefits/conditions. This is a shared goal of conservatives and business owners.

This also further divides people because of the consistent use of the "Welfare Queen" [1] stereotype by conservatives to vilify people on welfare.

0 - https://reason.com/2021/06/01/the-bipartisan-war-on-work/

1 - https://en.wikipedia.org/wiki/Welfare_queen#In_political_dis...

Easier lobbying for increased immigration, H-1B visas, and other "necessary" sources of (easily exploited) labour to avoid rising wages.

Gov assistance

Possibly in some countries increased education spending. Thus in future increasing labour supply. And complaining is pretty cheap...