Modern uPVC doors are a lot better these days than some of the old tat that used to be about. The usually have 5-point locking which mega -secure. They can be fitted to timber doors, but do add quite a bit to the cost.
Timber doors do take a while to fit them properly, especially fitting seals that match up to the efficiency of vPVC weather seals.
It's purely a matter of choice.
In a period building, most people go for timber every time. If it's a regular estate new-build or a bungalow, uPvc doesn't look out of place.
My biggest complaint is the diabolical brilliant white! I must admit I always paint plastic doors. It's surprising how much better they look then.