My experience is very different from many here, three of our children attended our large local primary school, (they are now 22,24 & 27), their school had 46 different nationalities and a much higher ESOL pupils, coupled with much higher mobility.
The school took the decision to embrace this, any child arriving with little or no English immediately attended a two week English immersion scheme, parents were encouraged to come in and learn with their children, special assemblies were held to give all children an insight into the countries these children originated from, there were “special” lunches so children could try their food.
My favourite time was always Christmas, there was always a traditional Christmas nativity from the infants, it was great to see a mix of many nationalities, religions, colours, all taking part (Patents were written to prior to this and always given the option to withdraw their children, to my knowledge, none ever did)
I was a school governor, deputy chair, for 10+ and had the privilege of spending time in the school regularly, eating lunch with the children, reading, watching shows and assemblies.
None of my children were adversely affected by the high levels of ESOL, much due to a very strong Head and her amazing Senior Leadership Team.
Of course, in these times schools were adequately funded.