I was in the same situation last year and I relocated back to UK with 2 young kids. I did a quick pro/cons below. Obviously we all enjoy the lifestyle that money can provide but with young family, for me it became a lower priority. The way I see it, if I don't like UK then I can always move back to HK but given the current situation, I would much rather be here in UK.
+lower humidity, I dont know how I survived hk humidity and air pollution
+education is better, oldest daughter is definitely happier plus local schools are free
+finally able to buy a house with garden
+I live in a commuter town, the air quality is so cleaner and different
+pleasure owning a car and exploring places with my kids
-higher taxes but there are ways around it eg self employed contractor, pension tax relief
-slower pace compared to uk and things here are so laid back
-I forgot I hate dark UK winter and of course the rain, it is bad this year
-no helper and child care can be expensive if they are young
-8million unemployed, claiming benefits
-increasing racism due to virus