Nothing is really going to protect you from a direct lightning strike. Lightning strikes are on the order of millions of volts and thousands of amps. It will arc between circuits that are close enough and it will raise the ground voltage by thousands of volts too. You basically need a lighting rod buried deep into the earth to prevent it hitting your house directly and then you’re still probably going to deal with fried electronics (but your house will survive). Surge protectors are for faulty power supplies and much milder transient events on the grid and maybe a lightning strike a mile or so away.

Would a UPS protect against that either, though?

No. Current will find a way. Lightning will destroy things you didn’t even think would be possible to destroy.

So I'm still left with int0x29's original question: "Isn't this [an electricity spike that a UPS could protect against] what a surge protector is for?"