What is wrong with my computer?

I built this PC about 3 years ago at this point with the intent that I would be able to use it for gaming as well as general activities like YouTube and so on. However, after about a year it started spontaneously having problems with no explainable answer. I have posted 2 other questions about this in years prior but the problem just keeps evolving. Originally it was repeated BSOD errors of the same error type, then it was BSOD crashes with a different error code every time, and now I get BSOD errors every once in a while alongside random game crashes and Windows error restarts with no explicable reason as to why they happen. This has also gone from only happening when I am in games to happening even when the computer is simply idol. My PC was fine for a few months after my original two problems but at this point there are so many different error types that I don't even know what to fix anymore. And believe me when I say I have tried everything short of just building a new PC. I have done virus and general security checks with Malwarebytes, Norton, and Windows Defender. Updated every conceivable driver and scanned / repaired all possible corruptions on a consistent basis (even though there usually aren't any). SFC scans, verifying files, system reboots, BIOS checks, minidump files, hardware checks through both software and physically checking and cleaning the hardware. I made sure all parts were compatible when I bought and built the PC and have triple checked at this point to make sure I didn't mess up somewhere along the line. All hardware pieces are still in good condition with no signs of deterioration or damage, my system never shows any software issues, there is no third party or malicious software on my PC. I don't even really expect an answer to this, I am just completely at a loss for why there is no explicable problem with my PC and yet there seems to be a flavor of the month error every day when I so much as turn it on.