WindowServer High CPU usage while connected to external monitor - Big Sur

So apparently there is this thing called WindowServer which is draining my cpu and consuming a lot of energy.

I have a Macbook pro (without mac os monterey (quite old macbook) but still running pretty smoothly) but since I installed the mac os big sur, after a few hours of operation, the CPU load of the Windows server process sometimes increases to 100%, no matter how many windows I have open - even if I then close them, the CPU load of the process always jumps back to high values! this strange behavior starts occurring as long as my external monitor is connected to my mac.

This usually happens when i'm off for a certain period of time with my screensaver turned on on my monitor and macbook's screen; When i spend some time gaming or watching a video on youtube;

etc.

So, few bits of context

• I've got a MacBook 13" 2014 dual-core intel core i7 (with mac os big sur, cant install mac os monterey, too old for that)
• It's connected via HDMI to a LG FHD Display monitor.

I'm experiencing a few things:

1. Stuttering when I move windows (like dropping frames)
2. WindowServer in Activity Monitor shoots through the roof of CPU usage when I move my mouse a lot
3. very loud noise stars to interfere with the music that is playing at the moment

As shown in the screenshot, i was out for the day and when i came back to my office, my live screensaver was lagging a lot, as well as the cooling turbines were spinning so aggressively it seemed like my computer was preparing to take flight:

I have seen a ton of people having the same issue, and throughout the internet i couldn't seem to find any good solution, or at least one that worked for me.

Is there anything that could help windowserver stop draining my cpu?