A 40 watt iron is possible, but barely. I used to use it. I had to turn off the fan lol. And it had better be a warm day. Even then it struggles with 14 AWG, and simply cannot work on 12 AWG.
That's when I decided to upgrade to an 80 watt iron.
Somebody mentioned RoHS. Actually quite a misguided regulation. They wanted to reduce the amount of lead being disposed of, and I think prevent it leaching into water sources. The problem was something like 90% of waste lead comes from used 1:1 scale car batteries, not electronics. I believe car batteries can be recycled.