[kuschku]

Even if you ignore the keyboard and the ports, the M1 has significantly worse battery.

The M1 13" has 58Wh, the M1 14" has 70Wh. And while the M1 does use less power in idle, under load it's just as power hungry as all the other processors, so for serious usage the battery would become a bottleneck.

The aforementioned thinkpad can get 95Wh, and you can swap batteries if you carry a spare. That's 170Wh of power in just 1.6kg. You can get a LOT of mileage out of that.

Now imagine an updated T470 with a more power efficient processor, e.g. a recent ryzen or an M1. Such a hypothetical device would last you forever, even if your system is at full load.

[turtlebits]

You can't compare battery capacities with the M1.

Under load the M1 uses significantly less power than any current AMD or Intel CPU.

I'm pretty sure the M1 would last longer than your T470 on both batteries (95Wh + 75Wh).

[kuschku]

The M1 Max draws in Cinebench single thread 11W, in multi thread 34W.

That's not much, but it's not the 2x-4x more efficient it'd need to compensate for the smaller battery.

Only for idle, browsing, video en/decoding, etc will you see significant improvements. For developers, the M1 is close, but not perfect.