I use a property manager.
Unless I have some business need to visit the property and happen to meet an existing tenant, I have no idea about how old they are other than at least one person is a legal adult (which might be less than 18 if an emancipated minor).
The only reason I know the tenant's name is because we send a Christmas card with a 1/2 month's rent as a gift if they've been there a year and taken good care of the property.
That name is the only clue I have to the tenant's gender or race or ethnic background, and we all know that's not reliable.
So if I wanted to re-purpose a property that a tenant was in, I could end up sending a notice to a 150 year old for all I know.
Now, if someone told me the person was 102 years old and they had also been a good tenant for 30 years, it would take a really compelling reason for me to proceed with my plans. If I absolutely had to move her out and she didn't have family to help, I would ask my property manager to help her find a place and (unless I was broke) hire some people to help her pack and help her move.
Not because I legally have to. But because I can and it's a nice thing to do. It's really hard for older people to move. It takes a lot of energy to look for a place, pack things up and unpack them.
I own 6 houses, 5 of which are owned free and clear. I can afford to be nice to people that old, particularly if they've been a good tenant for 30 years.