Does full power backup really matter for rental yield?

Does full power backup really impact tenant attraction and rental yield for flats like at Keya Life By The Lake? I'm looking at a 2BHK there, and they promise full flat backup. But I've heard some places only do common areas, leading to unhappy tenants. Also, how reliable is the water supply? Don't want future tenants complaining about tanker dependency. Should I push for specific clauses on these in the agreement? My budget is tight, so every detail matters for future ROI.