This is the 15110th most frequent Russian word.
полезнее
"More useful" or "more beneficial."
Here, 'полезнее' is used as a comparative adjective to describe one item being more beneficial (healthier) than another.
Фруктовый салат полезнее торта для здоровья.
Fruit salad is healthier than cake for one's health.
In this sentence, 'полезнее' highlights the comparison between activities in terms of their usefulness or benefit.
Изучение нового языка полезнее, чем просмотр телевизора.
Learning a new language is more beneficial than watching TV.
The word 'полезнее' compares activities to emphasize the health benefits of one over the other.