Since the Hogwarts incident, the British magical world had unexpectedly enjoyed a rare, brief period of peace. Even the Death Eaters probably realized that if they kept causing trouble, not only would they fail to gain the upper hand in their struggle against Albert, they might somehow get themselves killed. So they finally settled down.
Of course, another reason was that Voldemort had remained abroad searching for the wandmaker Gregorovitch. After suffering repeated losses, the Death Eaters dared not keep stirring up trouble without him there to lead them.
No one thought they had lived too long.
As for the main reason Voldemort had not returned to Britain, Gregorovitch had stopped hiding, while some brave and fearless Dark wizards who had drunk Polyjuice Potion were still active across various European countries.
Even though Voldemort had likely realized that someone was toying with him, he still had not given up searching for Gregorovitch and the legendary Deathstick.
As a result, things were not going well across Europe. People died every few days. Though there was no proof that Voldemort had done any of it, everyone was more than happy to pin the blame on him, because Voldemort would never come forward to deny it.
Voldemort, the ultimate scapegoat—everyone who used him knew how useful he was! After doing so many "good deeds," Voldemort had finally gained a bit of fame throughout Europe.
Everyone was trying to figure out what Voldemort was wandering around Europe looking for. Then the wandmaker Gregorovitch entered people's sights.
The newspapers had even reported it openly, and everyone was curious why Voldemort was looking for Gregorovitch.
Unfortunately, no one knew where Gregorovitch was hiding. Otherwise, wizards from the various countries' Ministries of Magic would have been delighted to capture him and send that harbinger of disaster out