Taxing income is straightforward in that there is a stream of it going by and some of it can be diverted. Taxing wealth is difficult because you don't really know what it is.
Arguably the value of a publicly traded corporation can be known because it is being traded continually. [1] For a privately held corporation it's quite opaque. Right now, for instance, Open AI is estimated to be worth $500B and might IPO at $1T but for all we know it could be a smoking hole in the ground in two years. Should we charge them a big bill in 2025 and then have the investors asking for a refund in 2027 when the real value is revised down to negative? Owners of imagined wealth could face big bills that, in the end, they couldn't pay. [2]
There would certainly be an incentive to avoid the taxation by minimizing bubbliness which might be a good thing but administering it would be a nightmare and manipulating the system to hide wealth would become a national sport.
[1] ... but it could be wrong seen from a future viewpoint
[2] I spent a lot of time in the 2010s calling up people in financial services on the phone and talking on the phone and there was no phrase that struck more fear into them than "mark-to-market", I could hear the voices crackle and feel the flinch. A bank or other institution that is perfectly able to make all its obligations as they unfold over time could be nominally insolvent at times when the market fluctuations down but winds up OK in the end -- the kind of accounting it would take to make wealth taxation accurate might be the end of fractional reserve banking and send us back to the giant Bitcoins of the Yap islands.