For where we use the stroller, when the baby was wee I popped the carseat into the stroller frame pretty much anywhere we went because it was very easy, grocery store, shopping, out to lunch, going to the park, doctor office etc. I used it interchangably with the ergo, but the infant carseat was easier if we had driven somewhere and he was already in the carseat. Once DS was a little older I bought the Boba air, and that was convenient to put him in because I would carry it with me all the time in the diaper bag.
https://www.planetbambini.com/blue-boba-air-baby-carrier/
Once DS outgrew the infant carseat (by height) and was in the chicco nextfit convertible carseat, we kept the umbrella stroller in the car and that was our go to, esp for the mall or a quick walk somewhere. Otherwise if I'm going to Target, per se, he rides in the cart.