The use of the present perfect relates the experience to the present moment. If someone says "It has been a remarkable journey" or "This trip's food has been great", we'd understand that they are referring to something that is finishing or has just finished.
The first example sounds like a figurative use of the word 'journey', meaning a transformative experience. You're perhaps saying how much you have learnt about yourself or about others over a period of time, and you're emphasising its positive effect on you. You'd use a present perfect to emphasise that even though the 'journey' has finished, the impact remains.
With the second example, you might comment that the food 'has been great' on the last day of your trip. You'd use a present perfect because the period of time you're referring to - the trip - hasn't quite finished yet.