MacBook Air M1 2021 gets warm quickly and uses a lot of battery?

Short question I noticed that my Mac book gets quite warm after a while with small things such as running YouTube in the background and writing on pages and also consumes battery relatively quickly. My Mac book should be clean. I regularly delete junk files and make sure to keep it tidy. I usually don't turn it off after use and leave it in sleep mode, even for several days. If I shut down the laptop and start it up again the next day, the problem persists, but if I quickly restart it, the restart function will keep it cool for the next time and use extremely little battery, which is kind of weird and I have the feeling that something runs in the background. I have already checked the activity display, but the utilization was not really high and did not rise above 10%.

Does anyone know what the cause is?

So YouTube is by no means as small a thing as you think. Depending on the resolution, the graphics cores (not the CPU) run to the limit and a lot of data is loaded via WLAN. That alone can contribute to your MBA getting warmer and losing battery faster.

As a tip, I would advise you to test a different browser. Safari is a great browser, but YouTube may run better in Chrome.

The strange thing is that after restarting the laptop I can have 30 tabs open, watch YouTube and the case still stays cool

Mine also warms up quickly and fills up, the fans need a lot of power, I think that the Apple logo on the back is unnecessary and that it lights up, makes something good, but it is a waste of energy.

I have the Mac book air m1 2020 there's not lit and it also has no fans

It's not exactly weird. Some websites like to "hang up" and Safari sometimes shows a small message above that a website uses a lot of energy and should be closed.

This usually doesn't happen immediately, but only after a while, for example when a certain advertisement is reloaded. The site may still react normally, but some script is running amok in the background.

In the activity display there's also the Energy tab, where you can see which processes use the most energy.