Compare frozen and fresh food prices per serving.
The structural advantage of frozen food is that you take what you need and the rest keeps, so spoilage is effectively zero. Fresh food is bought as a whole pack against an uncertain schedule, and the portion that goes off is money spent on food nobody eats — commonly 15 to 30 percent for produce in a typical household. Comparing cost per portion actually eaten rather than per portion purchased is what makes the comparison honest, and it regularly flips a decision that looked clear at the shelf price.
Frozen cost
Per portion = pack price / (pack g / portion g)
Fresh cost
Per portion eaten = pack price / ((pack g x (1 - spoilage%)) / portion g)
Because you portion from the bag and reseal it. The remainder returns to the freezer at the same quality, so nothing is discarded on a schedule. Frozen food does lose quality eventually, but on the weeks-to-months timescale of a shopping cycle the waste is essentially nil.
Generally no, and often better. Frozen vegetables are blanched and frozen within hours of picking, locking nutrients in place, while fresh equivalents may spend a week in transit and storage losing vitamin C. Texture is where frozen genuinely loses out.