I've found it really intersting to compare my 2 kids' experience of KS1. DC 1 attended a standard cookie-cutter academy. Phonics was well taught. We read copiously with the kids anyway and DC1 was reading independently and fluently by the end of year 1, even including covid stoppage time. The fundamentals of phonics teaching were there, the materials were really good and leveled properly and it was therefore dead easy to supplement with 20 minutes a day.
DC2 has been in a frankly appalling international school since the end of nursery. The phonics has been diabolical, no proper materials and virtually no teaching. She is so behind her peers in the UK. But because the school hasn't done the basics, it's very difficult to scaffold on top of those- we have no idea what she's done, where the gaps are and she then gets very cross with us when we do flash cards etc as she either finds it very hard or way too easy. We've had similar issues with maths- I understand Singapore maths approaches but they haven't been consistent so it's very hard to teach at home.
Couple that with the kids being out of the house from 07.30-4.30 and therefore knackered, it's hard to catch up.
The broader point in all this is that where you are using approaches that need some structure in their approach, the school needs to provide that structure or it's so difficult to catch them up and support at home. Most parents cannot provide a structured phonics or maths programme at home.
I also want them to do free play, exercise, be creative, be outside and relax. I don't want to cram formal learning into every second of the day- there's so much other learning to be done.