Investment: the action or process of investing money for profit or material result.
Profit: money in - money out.
You're just trading the stream of money that goes into rent for the stream of money that goes into taxes and interest on your loan.
You can't say "owning is better than renting" or vice versa without crunching the numbers for your particular situation.
When I bought my first house I was paying out more every month (by quite a bit) than I did as a renter. Then I rented for awhile and bought my current place, in which I come out ahead vs renting.