Major CPU spikes, CPU time & Hot with low demand apps

I just purchased this labtop from a reputable refurbasher. It has 16 Gigs of RAM and a quad core 2.7 Hz i7. Has a 128 Gig SSD Hardrive and runs Catalina 10.15.7. For whatever reason, the machine is taking major CPU loads from seemingly simple and basic tasks, like playing Youtube, Spotify, or just running any kind of video. I tried playing an old low demanding game called civilization 5 from 2010 which even my old 8 Gig mac can play fine and it ramps the heat of the mac up to the low 80’s for degrees C. The fans are constantly running, and even when idle the fans are always ramping up heavily intermittently up to 5000 RPM. When I look on Activity Monitor, many of the apps, even basic ones such as Activity Monitor itself, are running massive “CPU Time”(s) ….around 46:56:22….and that’s just one of many. I’m unsure of why theres such a heavy load on the system when its supposed to be fairly high performance. I bought this mac to record HD video and process high quality audio, but it seems to be overloaded with even the most basic of tasks. Ive tried running things with AC in and unplugged, same result. I’ve used “Drivedx” for system monitoring and everything shows “Ok”. The only reading that shows anything suspect is the “Temperature” bar that is reading at 44%, but still “Ok”. Coconut battery shows that the battery is also running fine, but when I play the basic game aformentioned, the battery dies within an hour. Any takers on this one??