I remember in the 80s tv repairshop they use cold spray or freeze spray on the components that were generating intermittent faults.
The fun part was that freezing it sometimes made it work again so you knew what the cause was.
With "dead" power components the spray would not evaporate so you knew that was the issue.
So a thermal cam is just another tool on your belt but I don't think it is the holy grail.
What stands out for me is that seeing all those computer laptop repair videos the powermosfets are 80% of the cause. And many are not even two years old. Is that bad thermal design, bad pcb design, underrated fets? It really look symptomatic for todays products.