Wow! Ain’t that wierd? Mine is as good as gold. The only real let down is the screen: low-definition and I can’t get the colours right, and I’ve tried many ways. In it’s defence it is a business-type laptop and graphics capability was probably not a priority for Dell. As a workhorse it’s still fine.
Oh, I did put a SSD in as well as upping the RAM, so that certainly perked it up a bit! 
Yeah, if you look at the 5440 on paper, there’s no reason for me to hate it. While obviously it’s quite outdated at THIS point, when it was still modern, as you say, the LCD was really the only true weakness of the system. But I owned 2 (maybe 3) through happenstance and stupid decisions and all of them had CONSTANT issues. So I grew to hate that model. We also had them at work, and we had a bunch of issues with those as well (not entirely their fault, 3 years old being used every day at home with 3 dogs and you never even tried blowing off the fans? And you’re wondering why it’s trying to light your desk on fire? REALLY…).
Mine runs EOS i3 now… I mainly use it to learn Python on. While just using Vim / VScodium it stays cool too… just can’t open a web browser without burning my lap.
It’s quite understandable that yours doesn’t have any thermal issues… It’s quite a bit thicker than my 7450, so it probably has a better cooling solution.
I’m not too worried about it though… I have a newer laptop with a Ryzen 3500u in it, that’s thinner and lighter, but hardly ever heats up. Just doesn’t have the awesome keyboard that the Dell has 