France made that mistake years ago:

Google AI Overview
France's previous wealth tax (ISF) is widely considered to have backfired due to high administrative costs, difficulty taxing illiquid assets, and incentivizing the wealthy to leave the country, which reduced the tax's overall revenue. Estimates suggest the tax may have cost France more in lost revenue and economic activity than it generated.
Reasons the French wealth tax is considered a failure
Revenue shortfall: The tax generated significantly less revenue than projected.
Capital flight: The tax prompted wealthy individuals and their assets to leave France, resulting in a net financial loss for the country. One estimate from 2006 suggested 843 people left the country due to the tax, resulting in a net loss of 2.8 billion.
High administrative costs: The tax was expensive and complex to administer, according to reports by the OECD and others.
Distorted investment: The wealth tax distorted saving and investment decisions, as people sought to minimize their tax burden. For example, controlling shareholders might have prioritized dividend payments to increase cash holdings for tax purposes, even if it was not in the company's best long-term interest.
Low threshold: The tax had a low threshold (1.3 million in assets), meaning it applied to a large number of households, which complicated administration and limited its revenue potential.
Poor design and loopholes: The policy included poorly designed loopholes that facilitated tax avoidance and further limited the revenue that could be collected.
Reforms and current status
France's wealth tax was abolished in 2017 by President Emmanuel Macron and replaced with a tax on property, not business or shares.
Even with the abolition, the issue remains politically contentious, with wealth tax proposals being debated again in late 2025.