is it good to add soil to my potted veggies and fruits?

I would advise against adding more soil

I did the same thing with my pepper and chilli plants Lovegreen and waited until they had grown a bit them just added some more soil on top. They're all still really healthy and I now have produce from all the plants. Might just be beginners luck but hope that helps! :-D

Thanks moongrower but I already shooted and I'm asking questions later which isn't good but maybe I'll have some beginners luck like Fireballjools

Depends on what is in your pots...

With tomatoes,I always try to bury the roots deeply to allow extra roots to grow,and when in big pots in the greenhouse I try to curl the stem further down into the pot for the same reason.(I have broken stems by doing this).
In the Dominican Republic,where my son was living, he used to lay the stems in the ground up to the first truss,and claims that they would grow up the trees.Of course,no seasons to consider either.
I think the extra soil can only help tomatoes,and I personally always top up with more compost thinking that if it is good for the toms it is possibly good for everything else.
I am aware that I could be wrong about this.

thanks justvera and moongrower i have toms, peppers and cucumbers.