The Fujitsu Lifebooks were legendary for their robustness back in the day, I'm genuinely sad you had that experience.
The only fujitsu laptops I used was back in 2011- it was a budget version for on-call and it was fine..
Sounds like the fans running 100% probably contributed significantly to the issue here. If I had to guess it was likely that the C-States were disabled in BIOS somehow so the CPU clock was running at full tilt the whole time, maybe combined with a bad thermal paste job.
I'm not here to defend Fujitsu but I've had really bad experiences with basically every major laptop brand (Dell: majorly bad coil whine and especially faulty soldered RAM, HP: keys vanishing from the keyboard and very weak hinges that break all the time, Apple: The GPU unsoldering itself and the butterfly keyboard shenanigans).
I don't really know any brand with a flawless track record sadly.
Before anyone brings up Thinkpads, they're trading on a reputation that hasn't been true for over a decade. If you have fond memories of a thinkpad it's most likely that you had it from before 2016, or it's "fine", but certainly not great.
I do recall that Fujitsu had a very... unique approach to exposing the Setup option in their firmware. It was just a UEFI boot entry. If that entry was removed, you couldn't get back into the firmware setup; you had to find the name of the setup EFI file and then run that from the EFI console.