No, 5 year leap was not needed. At most, they could have shown few months (5-8 months) the time it took for PF to settle in Agra and Radhika to do find teaching type jobs. But, they wanted to add a child as that would be the hurdle between Dev and Radhika as otherwise there is no reason for Radhika to not take back Dev even if he got married again as legally and religiously she is his wife. But, if there is a child, then they can show RAdhika crying buckets and eventually backing out from Dev's life out of sacrifice. Also, they had to show the RP melodrama at the last minute which could have been at any time between 5 years.
The main reason for the leap, making PF dirt poor, Radhika acting like a servant, Amma type characters etc is that they are copying from all the other top rated serials. Agle Janam had a leap, PR is going to have a leap, Bidaai is going to have a 8 year leap and others may be doing it too.
If you look at overall ratings of all soaps compared to last year, all of them have gone down. I believe that people are really getting sick of these stories, but the creatives don't seem to understand it. Saas bahu type serials ended when people stopped watching them. They then brought these rural or small town based serials with different type of stories which people liked, but now after one year all of them are going back to one hero and two heroines or other way. So, the ratings have started going down again.
I think any new serial should be given one year of time to complete and that way they can properly manage their start, middle point and end. No daily soap has a story beyond one year.