Ive got an Pentax K-r DSLR camera - tech specs here, this camera is about 9 years old. And i have the stock 18-55mm lens.

Ive also got an iPhone 11 Pro - tech specs here

Both have circa 12mp sensors, which sensor is better ? And which camera would ultimately produce a better image ?

I intend to use either for some interior photography, so its a 'planned use' rather than an adhoc requirement. If using the iPhone i would do it on using a iPhone to tripod adaptor.