The video is a bit long, but it highlights the problems with demographics and government spending, population expansion, the welfare state, and inflation.
Although the video is about England, it applies equally well to the United States. Although England has a National Health Service which is unsustainable, around 60% of health care spending in the United States is funded by the government. Regardless of which country you are in, the government is not going to have the money to keep all its promises.
These kinds of problems aren't unique to the United States and Great Britain. It is happening everywhere. China faces a demographic crisis because there aren't enough young people to support its aging population.
I was a little bit disappointed by his Climate Change views, calling it an emergency, but he points out that the next generation will have to produce 88% less carbon dioxide. This is completely unfeasible. A great many people are going to freeze in the wintertime. Far more people die from cold than they do from heat.
Population increase has always been a concern of mine. It puts pressure on finite resources and makes them more expensive. The cost of housing has reached insane levels, as have the property taxes on those houses.