Land tax is one of those things that you can value easily and collect on easily. It also hurts people who just sit on land, waiting for the value to go up. It also stops negative gearing which drives up housing prices (see Australia)
I think taxing wealth is harder and then defining it is hard (how do you value illiquid shares, options, etc).
You can also have an exemption for the first $1m so that family homes are excluded from the tax.
I think a straight wealth tax should be the next step, because you will need to figure out how to stop people dodging it. Taxing someone who has a ton of debt and wealth might lead to issues.