The reason is simple. Those three countries all implemented lockdown way after the horse had bolted.
Spain locked down when there were over 5k cases. UK nearly 4k. Both countries had well over 100 deaths by this stage.
Let's look at Greece.
On the 27th of Feb when they had 1 confirmed case they cancelled carnival season. They closed schools on the 10th March when cases had reached 89, still no deaths mind you. 3 days later, the day Spain locked down, Greece closed bars and restaurants, 190 cases and 1 death.
Locking down early was the key for Greece having such low numbers. They took preventative action, like New Zealand, the UAE and others.
The three countries at the top of the European table took their time and then thought fuck.