Prop 19's targeting inheritance exemptions will have uneven effects. The very wealthy won't be affected at all because, on the advice of their estate planners, they will have transferred their properties into corporate entities long ago. (Recall that properties owned by corporations aren't reassessed when stock ownership changes and Prop 19 didn't change that.) Heirs to properties worth less than $1m who intend to use the property as a primary residence are also unaffected.
There is, however, a large group of ordinary middle-class people, particularly in cities like Los Angeles or San Francisco, who own what were once modest homes that are now worth more than $1m.[0] Their heirs will be burdened when the property tax bills double (or more) in one year, even if the heirs use the property as their primary residence. More heirs will sell inherited properties, which is exactly what the real estate brokers who promoted Prop 19 intended. $1m+ is also a sweet spot for broker profitability.
The intent of Prop 13 was to stabilize property taxes after the double-digit hyperinflation of the 1970s by capping annual increases in assessed value at 2%. That created stability for individuals and businesses that led to massive investment in and migration to California.
Prop 19 undoes that stability, but only for a narrow group of people: heirs to $1m+ properties from parents who did not have sophisticated estate planners. From Wikipedia:
The Case–Shiller housing index shows prices in Los Angeles, San Diego, and San Francisco appreciated 170% from 1987 (the start of available data) to 2012 while the 2% cap only allowed a 67% increase in taxes on homes that were not sold during this 26-year period.
[1][2]. On average, heirs to $1m+ homes in those markets will be hit with roughly a 103% increase in one year (170%-67%). So, Prop 19 hits a narrow group of people with a 100%+ tax increase when Prop 13 was supposed to limit increases to 2%. A compromise rule could have been to spread out the increase over the course of a few years, but that wouldn't induce more sales like the brokers' lobbying group wanted.
Personally, I think it would be fair to increase the annual cap from 2% to 4%. In a decade or so, that would undo much of the tax discrepancies caused by Prop 13. And the effects would be spread out, so people could plan for it. Increasing the cap, however, would never pass because it is clearly a tax increase on everyone and doesn't benefit a special interest like real estate brokers.
[0] The median home price in Los Angeles is now over $900k. https://www.zillow.com/los-angeles-ca/home-values/
[1] https://en.wikipedia.org/wiki/1978_California_Proposition_13...
[2] https://web.archive.org/web/20191011004252/https://us.spindi...