People have suggested a wealth tax, but there are issues with that. Some want to tax assets, but there are issues with that.

How about removing property tax, and instead taxing land at a higher rate? The wealthy (top 0.1%) are continuously buying up as much land as they can. If we tax land based on it's value more appropriately, we will see more land being sold, more land being invested in (because property would be taxed less, and land more), and then more productive land as a result.

This would be politically unpopular amongst the rent seekers of our society, and likely have huge ad campaigns against it as a result. But the downsides compared to upsides see negligible for the public. More productive land, and more tax revenue from the owners of the land.