So, 90 of those hereditary peers are elected, just, they're elected by other hereditary peers. So, just because you're a peer does not mean you have the right to sit in the House of Lords, whereas before you could. If I recall, you didn't have to ever sit, but if you wanted to show up, you basically could come in to vote.

The other two hereditary peers are not elected. They have some ceremonial role (though they can vote) that was thought prudent to retain. I don't remember (if I ever know) what it was.