- dedicated 50A 240V for an electric stove or oven (unless gas service is present)
- dedicated 20A 120V each for the fridge, microwave, dishwasher, disposal (the latter being uncommon outside the US and Canada). The last two often share a circuit.
- two 20A countertop circuits with GFCI protection (what the Brits call 'RCD' - the difference being ours trip at 5mA vs 30mA and won't knock out half the house.)
A typical British kitchen will have a ton of sockets (although never enough), to plug in a fridge (or two, or three), a microwave (or several - they rarely goes about 1kW anyway), a dishwasher, a washing machine, a tumble dryer (UK kitchens tend to have washers and dryers, rather than bathrooms. Larger houses have separate utility rooms)
The only thing on a dedicated circuit would be a hard-wired oven.
A software analogy would be running all your services on separate VMs, as opposed to running them all on a single server which could go down at once.
Brits don't even put outlets in the bathroom, minus a current-limited transformer-isolated one for an electric razor.
Has never been an issue anywhere I lived in the UK. As I understand it they have been putting in 30A/230V ring circuits as standard for 75 years now.
Then, standard ring circuit is 32A, and individual sockets are limited to 13A (via fuse in plug). So you will need to have 2 kettles on on the same circuit and then add a third device pulling not an insignificant amount of power (32 - 2x13 = 6A) before the breaker trips. This will be safe if the ring circuit is not faulty as they are usually wired with two 2.5mm2 cables (two because it's a ring) that have a standard rating of 24A each...