While it's not clear who exactly is behind the attacks, the culprits don't appear to be checking for the presence of actual 5G -- one attack in Birmingham wrecked a tower that provided LTE access at most. The threats against engineers have sometimes been levelled at employees for wired broadband companies, not cell service.
The attacks have become significant enough that officials and company executives are speaking out. NHS England's Stephen Powis was "absolutely disgusted" at the attacks, noting that the phone networks were crucial to emergency and health care workers. Vodafone UK chief Nick Jeffery, meanwhile, saw this as a question of national security.
It's not clear if the government will crack down on these attempts. However, it's safe to say the anti-5G theories don't have a scientific basis. High-frequency 5G shouldn't be harmful enough to cause health issues by itself, and it certainly doesn't foster the growth of viruses. Moreover, COVID-19 infection rates aren't at all linked to the presence of 5G cell sites. Iran has no 5G service to speak of, for instance, but has still grappled with a high infection rate. Simply speaking, anti-5G attacks like those in the UK stem from irrational fear.