It’s useful for society if there’s a way for criminals to reintegrate into society.

If potential employers can always check for a criminal record, and refuse to hire criminals, then guess what those criminals will do? The answer isn’t “starve to death”.

Previously there were practical limits to how long a sentence could follow you. If you moved across the country, you might lose whatever family you still have, but at least you could get a fresh start. Nowadays that’s effectively impossible.