It's literally the basis for Thomas Piketty's 'Capital in the Twenty-First Century'. It's a dense book, but widely acclaimed. It was also published 8 years ago and the claims aren't controversial.

To say it's not controversial seems misleading. It may be widely acclaimed, but also hugely criticised. Wikipedia has a short collection of the criticism.

https://en.wikipedia.org/wiki/Capital_in_the_Twenty-First_Ce...

There are very few critiques of the empirical assertion that the capital share of the economy is not increasing, though. Most are on other parts of his thesis or argument.

There are critiques of anthropogenic climate change and the addictive nature of nicotine

Real estate (land to be specific) is a popular investment because it lets you extract economic rents.

You can build a dynasty around land because ownership is barely taxed. Land does not degrade by simply keeping it vacant. Meanwhile everyone around the land needs it to live on or to work or to extract resources. Inequality isn't driven by well deserved high returns, it is driven by monopolistic extortion where you cannot refuse even if you know you're getting ripped off.