My mum was like you, spurned friendships. That was fine when dad was alive and she was busy with her own kids. And even I suppose right until we started having our own babies and got busy, she would see plenty of us. So she didn't need friends. Now she lives alone, has done for 15 years now and she's a very fit 77yo so there's plenty of years (hopefully) to go.
But she still doesn't have friends, despite telling us she gets really lonely. Even former work colleagues that she got on great with or old family friends frequently invite her to do stuff and she declines. She's got no hobbies either. We've all had to move at least an hour away for work or for our own family needs so she doesn't have anyone popping in.
She says she's fine on her own and doesn't like talking to neighbours or anyone that knows her but she only talks to her offspring and her own siblings, nobody else unless they seek her out and then she can't get rid of them fast enough.
And for us, it's exhausting being the sole hobby and interest for someone. The absolute minutae of our lives is gossiped about to her siblings or to her other kids. So that results in me telling her fuck all really because I know anything private will end up in any number of whatsapp chats as juicy gossip fodder.
We aren't close and have a bit of a prickly relationship because from her POV she devoted her entire existence to her kids and probably sees me as being dismissive, difficult and ungrateful but it's actually self preservation from a woman who is suffocatingly overbearing.
I'm not saying you are anything like that. It's easy to be happy in your own company and not need friendships when you have the fallback of your kids and husband to spend time with but it may not always be that way...