The death penalty does solve the problems--with minimal expense. And for such as high treason, it is appropriate. Those that tried to ruin our constitution deserve to die--and not necessarily in the most humane way, either. They want us all to die a miserable death after being exploited as slaves, so why would I be in favor of even being humane with them, let alone letting them live at my expense?
But, for such as property crimes, or "crimes" that only go against some stupid religion, no. Such as homosexuality carrying the death penalty in Islamic lands, beheading for Noahide Law violations, and people being killed (and intentionally tortured) for practicing religions that might reveal Christi-SCAM-ity (judaism and islam, too) as false. And being killed or tortured because you didn't praise some tyrant "enough" is just plain bogus.
And such for animals? I have seen such as rats and mice killed, and often by being stuck to glue traps (and price tags that fall off store shelves), for the "offense" of just being in the wrong place. And no one thinks twice about that (I prefer simply evicting them by placing no-kill traps that simply imprison them, then releasing them well outside the place). So why would we think twice before killing, or even torturing, those who are bent on making life miserable for everyone on the planet while profiting from it?
Such as those who are pushing global mandatory torture shots (as coronavirus vaccines) for what amounts to a risk of catching a cold.