Not just UK. NZ cards have both dates, but i've never seen anyone ask for the valid from date.
Some Australian cards have a valid from date, but they are uncommon. That date really has no bearing outside of "When can I use my card?".
Typically with most banks here, once you receive your renewal card, it's active straight away (or you have to manually activate it using your banking app/website). Once you start using the new card, the old card becomes invalid automatically.