I'll try this to be short and on topic.
I am from the Continent, I've been living in the UK for nearly 15 years.
2 kids in state primary schools. DD1 one is taking his 11+ next year. The amount of study/tutoring that we have to do with him is shocking. Minimum 2-3 hours a day. It's because at school they do nothing. Like, every day is Harvest festival, mental health week, anty-bullying week, etc. but what about the actual curriculum and study? I think especially the math level is very low. And it's not like we've just recently woken up because of the exams. He's been doing the age-appropriate practice since Year 3. What I mean is, we bought the math books and did them with him every year. But at school they did maybe 1/4 of the content that is there in the books, so barely minimum that they could escape with, I guess. It should not be like this, because this means that if you don't have money for tutoring or you are not educated to a degree level to tutor yourself, your child has barely any chance of going to a good secondary school, even if they are academically gifted. Nothing is fair about this.
Now, about the infrastructure and the buildings. Most of the primary schools in Herts, where we live, look like some temporary garden sheds. Where I grew up, schools were proper brick buildings and the schools were quite big, with many floors, many classes, etc. How come these school buildings here pass any kind of EHS regulations is a mistery to me. However, the equipment and accessories at schools here are top-notch and that is great, cause I remember in my childhood years we didn't even have any toilet paper and teachers prepared their lessons using their own equipment and materials at home (and as kids we studied and did homework from books that we had to purchase and that was obligatory from the age of 7). And I won't even start about the poor pupil behaviour and lax parents' attitude, as last year the kids stood up during the class and started strangling their horrified friends in front of the teacher following some kind of Tit-Tok challenge. How on earth 9-year old kids are even allowed access to this kind of content is beyond me.
To sum this up, DD2 just started Reception in the local CoE school and I'm saving the money for the local private prep from Year 3. Not because we want to, but because we have no other choice, really.
I've had a chat with other non-UK born parents and we all share the feeling that here the state school is just like a social club for kids and primary purpose of the school, which once was to study, is now secondary (if not gone altogether). My son said once to me, "I just go there to play football...".
Finally, I know that this is biased and I'm sorry, it's probably because we come from high-pressure education environments where it was normal for us to study 3 hours a day, every day, and we had tests/exams every week. But still we managed to have a social life, so it's not like one excludes the other. And everybody, rich or poor, had a chance to study like this and succeed because every state school provided that chance and knowledge (private schools were extremely rare and only in big cities). Here I chat to a supposedly educated teacher who tells me that the capital of India is Mumbai and doesn't know the formula for the circle circumference. UK seems to have gone in the other direction - poor quality education for the masses and high quality for the rich/most determined (parents) - maybe it's the reflection of the old class division here? I'm not sure.