Updates to Android are regulated by your network operator in the UK. The network will receive the latest updates, they fine tune it with bloatware and release it.... HOWEVER.... if your phone is unbranded like mine and fully unlocked to all networks. It gets it straight from Samsung upon release.
Eventually they do. Last time I had a phone that was bought and locked by EE. And I questioned the android update release dates, EE told me they undertake rigorous testing and to be sure there's no problems. But it's all bull..... my S20+ on Android 12 works as good as ever on EE