It can be.
It really depends on the TIM used and the GPU arcitecture. I replaced the TIM on my 7900 XTX with a TG Kryosheet. Peak core temp is much better, but delta between hotspot and core is wild. Sometimes over 30ºC difference.
There is a reason why NVIDIA stopped reporting (or started hiding) their hotspot temps. They can lead to people worrying about an issue that isn't really an issue.