Oneplus Nord 2 exploded again.

No, I don't think its because of fast charging. There are several other devices with fast charging and they don't explode. The reason is still unknown, but we hope to see something in the future.

It is not the fast charging to blame. There are various other factors like heating, environment and battery.

In this case with nord2
This is some problem with the battery .. may be it's manufacturing defect ..
No other reason for it..

In Samsung's case in normal 15w and 25w many samsung phones are heating while charging ..
Samsung is fixing it through updates and all..
Fast charging makes the phone heat while charging but with proper optimisation and other designs they can control it to large extent..
Even now many phones outside India ate there with 120w and all..

Samsung should atleast provide 25w midrange or even 45w in premium midrange ..
In flagship 65w .
As we can disable fast charging in settings it won't be a problem for anyone who cares their battery life ..

Samsung can do it very well ..
But don't know y they are laying behind in fast charging department..

This happens when company focuses on quantity than quality

For such occurrences, fast charging cannot be held entirely responsible. There maybe several other factors behind this.

May be there is issue with battery

Like Note 7 Happend Before

This is china company so dont know they will recall devices or not like samsung does
Edit : Its Note 7 Not 5