Web surfing is subjective. Some websites/plugins can draw tons of power which will obviously result in the battery running out of juice sooner. I'm not up to date on the state of Teams, but it used to be a resource hog, so that might explain it as well.
I agree with >4h of light use... but... the M1 Pro in a 14" provides around 8-9 hours of light use (again subjective), the Max will eat up more power so that 8-9 hours drops a bit and even more depending on what you do with it. Plenty of reviews that show this out in the wild on YouTube. The 14" with its 67Wh battery vs the 16" with 100Wh is just not a really good match for the Max (even less so with with 32GPU core) and plays much nicer with the Pro. That + the usual issues with websites can result in quickly draining the battery.