Everything has a failure rate. It's never a matter of IF a component will fail, it's a matter of WHEN. The better the quality of the circuitry, the lower the chances of IF and WHEN.
That applies to psus and the stuff plugged into them. Can a psu fry a gpu? Yep, it's possible. And the lower the quality of the psu, the greater the chances of that happening. That's not to say it'll always happen, there's half a dozen or more things that all have to go wrong simultaneously, or the outputs on the psu have to be abysmally bad which just shortens component lifespans, but it is possible. Not probable.
TT brands everything in a psu line. They have absolute junk I'd not give to my ex-wife to seriously decent that I'd have no issues owning. Exact model/size determines that aspect.
There's also some priviso's. First, it's a 1080ti. It's aged. Could be it's just done. No fault on the psu. Could be the monitor, they don't last forever either, I've had brand new ones fail after less than a year. Could be the cable, could be that particular port, could be the motherboard pcie port, or even the cpu. Could be a combination of things.
That's something you'll need to consider before instantly assuming the psu fried the gpu.