Why did a power surge from a lightning strike take out my internet equipment transformers and not the devices?

A power surge from a lightning strike can induce a voltage spike that overwhelms devices connected to the electrical system. However, Transformers are designed to handle high voltages and can absorb some of the energy, which may lead to their failure while protecting downstream devices. Additionally, if your internet equipment was connected to surge protectors, they might have diverted the excess voltage away from the devices, preventing damage. This combination of transformer failure and protective measures likely resulted in the transformers being affected while the devices remained unharmed.