people are getting caught up in semantics instead of answering your question, so ill give an opinion as to why its different.

wealthy people are not subject to the same laws and punishments, based souly on their wealth and power getting in the way of the "normal" judiciary process. compared to similar crimes and punishments done by someone who is not in the same class.

the death penalty is also used as a tool to silence political enemies and dissidents, especially in political systems that align with fascism, authoritarianism, etc. (itll start becoming more common in the states, they will just label political rivals and dissidents as "terrorists" more often) whether they commited the crime or not.

essentially, why we may want to redistribute the wealth or "call for the death" of billionaires, its more so that out of everyone, even lowly murderers, their very existence, at the moment they HOARD 1 billion dollars, kills roughly 13,000 people who could have been lifted out of extreme poverty, by that same amount of money, per year, but instead succumb to poverty related deaths.

someone like elon musk as an example, just holding on to a (volatile) 348 billion, causes ROUGHLY 1,000 deaths per day, of people living in extreme poverty, just by him simply holding on to that money. the top 1% in general contribute to roughly 9,159 deaths per day just by hoarding their wealth.

21,500 people on average die from extreme poverty, per day.

they collectively contribute to killing nearly half of the worlds poorest people each day, so that they can have fancy things, and have fancy friends, and do fancy stuff.

that is colder than anything that even the most mentally deranged "lower class" serial killer has ever done.

at least in my personal opinion.