Is it best to still have access to your childhood home as an adult or are adults better off without that connection?

I think you have to do what you have to do. If you need money, you have to sell it. Having another place to stay at is nice but maintaining an uninhabited house can be difficult, especially in cold climate. Of course, you can still offer it for rent but then it's business, not a property you can truly use.
My opinion is that having strong ties to a house after it stopped serving you well is a huge burden and can actually ruin your life. In that case it's better to make a clean cut and start anew, move on instead of dragging the past along with you, repairing the old again and again and dealing with the clutter accumulated throughout the years.

Bit of both - I just sold my childhood home, but it wasn't the same as it was when I was a child and so didn't really feel as bad as I thought it would.

It depends if family stil live there
Some people continue living in their home as an adult !
It depends on circumstances

I moved too much/often to have anything I consider a childhood home, but I don't feel like I'm missing out.

I have no connection to former residences. My people have all left.

Both ways are actually nice

Nostalgia is great

I don't understand the question?
Are you referring to keeping a literal property from your childhood for sentimental reasons?
I don't think that most people in the Western world can afford to keep an extra house unless they are renting it out and using it to make money.

My mom's house is very old it was built in about 1902 or 3 and it's been in our family for a long time so we kind of all agreed not to never sell it besides that it's on a really huge property in the middle of the city so we really don't want to sell it no matter what happens. My mom is going to leave it to my little sister.

Not 'better off' i'd be more relaxed, having all my childhood memories constsntly surrounding me