Should the one who asks this question abandon leading the prayers in the mosque he frequents due to his fear of showing off (riya') and his good deeds becoming void, knowing that his reason for going to the mosque is to establish the rows without gaps?

It is permissible to create distances between worshipers due to an epidemic, and there is no harm in not straightening the rows at that time, as it is a part of taking legitimate precautionary measures. A Muslim should abandon the whispers of showing off (riya') and strive to do good deeds sincerely for the sake of Allah. Leading the prayer for the one who has memorized the most Quran is good and rewarded. Informing others about the extent of one's memorization with the intention of encouraging good emulation is rewarded. Obsessive thoughts about showing off prevent one from doing good, and displaying an action for a preponderant benefit is not forbidden.