What is the best thing about being alone?

Being Alone.
no obligation, no bullshit, no expectation, and no playing to people's egos or feelings. essentially, Peace.

You won't have a fraction of the problems

I suppose the primary one is that you're never bound by another's insecurities or needs.
Those of us who have had partners who were very needy, either in terms of their own self-esteem or their ego, controlling much of who they are and subsequently, who YOU need to be in order to accommodate theirs ! know this all too well !

It does make life lonely at times. But the freedom you get, away from all that, allows you time to tailor much of life how YOU want to live it ! For the most part anyway.

There are drawbacks of course. The obvious one being that you're constantly alone. You can always go places. Do things. Have friends even !
But there's no conversation. Nobody to share experiences with. And obviously no intimacy.

Doing natural things like burping and farting and feeling good about that.

Nobody will hurt you

There's no chance of acting on homicidal impulses.

Silence, and a feeling that's hard to explain

Easier to have an uninterrupted schedule.

you answer to no one. your time and money are your own.

Nothing to disappoint.

No one else is there

No robots

Freedom

🤷