Stability (your (fixed rate) mortgage payment doesn't change, control (within reasonable limitations, I can mount things to walls, pour concrete in the back yard, rip up the floors and put hardwood, etc), the ability to actually pay it off and no longer have to worry about the payment (even if its a long way out for a 30 year mortgage, you build equity instead of just losing all of the money), the ability to sell the house to recoup equity (not in an investment sense, just in a, this house didnt depreciate like a car would so i can make a significant portion of what i paid back when I do decide to move), among other smaller things.

The critical downsides in my experience are maintenance (no repair guy to fix your water heater), and being locked in, especially during turbulent economic times and personal instability (for example, it's difficult to 'up and move' for a new job.)

That being said, there are also legitimate reasons to rent, though I found as I get older, I wanted more stability, and less having to deal with a landlord dictating me (and being able to enter my house and decide how I behave) even if that means sacrificing some other aspects like better locations.

We only live one time, and I like being able to have a home that is mine and my families, it's given us a lot of opportunities, like being able to immigrate family members and have a place for them to live with us, something that becomes challenging when a landlord tells you that you can't have additional tenants, for example.