Lenovo IdeapadGaming 3, GTX 1650ti, AMD Ryzen5 4600H with Radeon Graphics, 16Gb ram (has all the latest drivers for both AMD and NVIDIA) crashes games like Valorant (lowest settings) but can run Witcher 3 at (high-ultra) smoothly, crashes on indie titles but can run doom eternal at 60fps. What are potential reasons for this to happen
Its likely the anticheat mucking up stuff. That game goes deep into your OS and injects itself to find cheat software. In times past, we called them rootkits and malware…
Probably give up on games with invasive anticheat?
Also, will not be ideal but maybe worth testing out, can you force the game to use the iGPU instead to see if the same thing occurs ?
Testing both the iGPU and the Dedicted GPU separately to get a better idea of the problem.
One other thing that may or may not help, run DDU to remove ALL the AMD software and ALL the nVidia software.
Be sure to have the latest driver packages store on the local disk to reinstall with.
Maybe an issue there ?
Also OP, try closing non-gaming related background services like Dropbox, RGB controller software and the like. Maybe antivirus as well (but only if you have a functioning Windows Defender).
I see could be the anti-cheat, but then games such as Arkham knight and small indie games should still work, but they also crash. Meanwhile, Elden Ring with an anti cheat doesn’t crash if I play without charger, but crashes with charger. 
I’ve tested drivers versions and done clean install multiple times. Unfortunately, I can’t rule in hardware problems, cause some higher graphics req games run with no problems
You can easily do so if you have windows 11