If you don’t pay attention to this point when buying your new phone, don’t say I didn’t warn you.

Different processor chips are evaluated based on four elements:
1- Battery (battery consumption speed)
2- Performance
3- Heat
4- Graphics
MediaTek processor:

Starting with the MediaTek processor, in terms of battery, it is known for its high battery consumption, and currently they are making developments to support lower battery consumption with the same performance. In terms of performance, it is known for its multiple cores, so its performance is very good and it can handle large and multiple tasks at the same time, but it is advisable to add higher RAM to give full performance. (Extra processing cores require additional RAM).
As for heat, MediaTek processors generate higher heat as long as they support adding and multiplying their cores (more cores equal higher heat). As for graphics, MediaTek uses an external addition (Mali graphics) to support graphics in its processors, so there is no compatibility between the processor performance and the graphics engine.
Snapdragon processor:

It is considered the best compared to all processors in lower battery consumption. In terms of performance, it is very good and can handle large and multiple tasks at the same time. It generates less heat compared to other processors, except for the Snapdragon 810 processor which faces several issues related to increased heat. As for graphics, Snapdragon uses a graphics engine made in-house called (Adreno Graphics), so the processor and graphics engine are compatible and work well.
Finally, when you want to buy a phone, if you want a cheaper phone that can handle heat and battery consumption, you should go for MediaTek processors. If you want a phone with good performance and no issues, then you should go for Snapdragon processors with a slightly higher price.