Of course not. While not strictly a ThinkPad, IBM used to make some very loud "communication devices" that Americans famously toted around the European continent in the 1940s; the largest batteries available for them still didn't push its weight over 6 pounds.

They seemed to manage that just fine. You can carry a computer across the office.

That aside, the extended battery on the T480 is still bad- it raises the bottom of the laptop and prevents the laptop from sitting flat. This was avoided on the older models by designing the hinges and lid properly such that the 100Wh battery would simply stick out the back but they don't make them like that any more.

I thought the same until I developed shoulder and back pain from carrying around too much stuff all the time. Be thankful that it still doesn't matter for you.