Agree, it was a success for us too. The novelty of being at school and learning routines, making friends etc was pretty absorbing, plus reading is a big focus of that year and the teacher was great at just skipping the reading ahead all year as necessary.
The next year was a stinker smile and the next two years reasonably better. From my POV it all starts to unravel about age 9 … if I could do it all again, I'd skip that second year.