Is my processor just too bad?

Okay so I've had a new pc for about a week. However, I had the problem that it kept crashing. At first I thought it was the electricity and bought a new power supply. Here are my parts:

Rx 5600x, Amd Ryzen 5 3500x, 700w, 2x 8 gb ram, 500gb

So, I have now always displayed the metric and sometimes when I render a video or play Fortnite for 20 minutes the PC just crashes and restarts. I've already looked at all kinds of research, etc. But I just don't know what to do next. I saw in the metric shortly before the crash that the CPU utilization was at 100%, so can it be that my CPU is simply too bad? I also only have one app open at a time, but it still crashes.

This is not due to the processor or its load. Normally I would tap the power supply, but you've already swapped that. In the first instance, do a BIOS update and reinstall Windows. If that doesn't help, then hardware is to blame.

No, something must be defective. The processor is significantly better than what many other people use. In addition, games don't just crash if the computer is too slow, they jerk if they do, but that shouldn't be the problem here either, this is an up-to-date, solid mid-range gaming PC, and all existing games should run without problems (Unless you choose exaggerated graphics settings now.)

As long as you don't limit the frame rate, it's not surprising that either the CPU or GPU are running at full capacity. Normally, the PC tries to compute the game with the maximum frame rate, and then it can happen that it uses one of the components to full capacity, no matter how fast it is. You can try to limit the frame rate to the refresh rate of your screen, or a bit higher (e.g. I have 144 Hz and usually set it to around 160 FPS.).

One reason for the crashes could e.g. Insufficient cooling or a bad power supply. But it could also be a software problem.

I limited my FPS to 160 and I use the cooler that I got with me

Is the standard cooling good enough?

I've done it before and it didn't help

what hardware could be to blame?

Uff hard to say

Try a different graphics card