Dear it would not make any significant difference. It has just become a psychy that people change stock rims and tyres and for addes show-off or improve the look of the car add alloy rims, otherwise there is not a big difference.
These wheel tyre shop wallas would always say that steel rims are bad, General tyres are bad to sell their stuff.
A good wheel balancing, alignment shop would never tell you that especially for a new car.
The alloys available in market are mostly not trouble free and issues crop up soon when you put them on.
And finally if you have bucks to spend, go ahead and change tyres and rims.