There are tons of things that cause my MBP to burn through power. Slack is the most obvious. Then, you have Chrome that will sometimes fire update some high rendering page.
The most sure fire way to kill the battery is fire up an IDE and do any sort of software development. Introspection, compilation, specs, etc all take up a bunch of battery.
With that being said, you certainly don't need 100W for a laptop. In fact, I'm not even sure my Mac can cool itself appropriately with high CPU usage and 50W of power.
Most people could get through a full day with a 15W charger. Laptop might be nearly dead at the end of the day, but 15W will fill it back up over night.
Anecdotal, but my M1 Max seems to drain battery very slowly with my daily development with all kinds of things running. Firefox, Brave, Slack, VSCode, Mail, docker containers, etc. It's pretty amazing how long they last.
The other day I even accidentally left Factorio running because I got distracted getting my kid ready for school, and I hadn't noticed until a few hours later in a meeting when I heard the technology research sound. It was not plugged in the entire time, and I still had at least half the battery life.
The most sure fire way to kill the battery is fire up an IDE and do any sort of software development. Introspection, compilation, specs, etc all take up a bunch of battery.
With that being said, you certainly don't need 100W for a laptop. In fact, I'm not even sure my Mac can cool itself appropriately with high CPU usage and 50W of power.
Most people could get through a full day with a 15W charger. Laptop might be nearly dead at the end of the day, but 15W will fill it back up over night.