Fused plugs still have a big advantage.

The amperage can be specific to the device.

We do mandate all circuits have RCD/GFCI now, but we're not taking away fuses in plugs.

If a lamp starts drawing too much current for its wire, it might be on a 20A breaker. It should have a 1A fuse in the plug.

Fuses on the sockets would mean either specific sockets and circuits for low, medium, and high power devices or a loss of specificity. In fact there are 5 levels, so 5 different levels to replicate with your system.

https://www.stevensonplumbing.co.uk/bs1362-fuses.html

For a short or earth the RCD trips. If more goes out on the live than returns to the neutral the RCD trips. If the current goes high but returns correctly to the neutral, the RCD does nothing, the fuse in the plug breaks.

Fuses are an inch by a quarter inch.

Fuses and plugs could be made smaller but to be honest the pins and wires need to be able to take 13A.

Most of the bulk is about the length of the pins. Making it mechanically safe so the earth connects before the live, making it difficult to accidentally pull out the wall, and making sure no live connection is contactable when partly outside the wall.

We have low power travel adapters for low power devices that fold away bits they don't need. Or separate onto pieces.

I think we're good. Plugs are still smaller than AC-DC adapters we use all the time. Calling the bulky is a bit of a stretch. They're aren't bulky, even compared to a modern phone charger.