Frozen pizza gets most of its bad reputation from being cooked incorrectly. A soggy base, rubbery cheese that separates into orange oil, and toppings that dry out before the centre is cooked through - these are all avoidable. The issue is that most people follow the packet instructions exactly, which are written for the lowest-common-denominator oven at an average setting. Your oven probably runs differently, and there are things you can do before and after baking that the packet doesn't mention.
Most frozen pizza packets say 200C. Go higher: 220-230C (fan). A hotter oven means faster surface cooking, which means the cheese bubbles and browns before the base has a chance to get soggy. If your oven has a fan, use it - the circulating heat cooks the base more evenly.
Placement matters: put the pizza on the lowest rack, directly on the oven shelf (not on a baking tray). The direct heat from below crisps the base significantly better than a tray, which insulates it. If you have a pizza stone, preheat it in the oven for 30 minutes before putting the pizza on - this is the single biggest upgrade available.
These go on before the pizza enters the oven:
This is where the gap between frozen and proper closes most dramatically. Add these immediately after the pizza comes out of the oven:
If you plan ahead: take the pizza out of the freezer the night before and leave it uncovered in the fridge. The surface dries out slightly, which means significantly less steam in the oven and a crisper base. It's the same principle as air-drying meat before roasting.
A standard frozen margherita pizza (300g) is roughly 680–780 kcal and 28-32g protein. Adding fresh mozzarella (+80 kcal, +5g protein), a fried egg (+75 kcal, +6g protein), and rocket (+5 kcal) brings the upgraded total to approximately 850 kcal and 40g protein for the whole pizza, or ~425 kcal and 20g protein per half. Adjust for your specific brand and additions.
Leftover pizza reheats well in a dry pan with a lid on low heat for 5 minutes - the base gets crispy again and the cheese softens without going rubbery. The microwave makes it worse; the pan method is the correct one. For more ideas on upgrading convenience food without much effort, see the full Instant Food, Elevated guide.