uPVC conservatories were popular up until about 2008. Then we all realised that they are usually too hot in the summer and too cold in the winter. They are not practical extensions to the home, and so often became dumping grounds or utility rooms.
A veranda room gives you usable outdoor space. In the summer it is much easier to regulate the temperature. Just slide the doors back and the temperature will reach an equilibrium quickly. Roof blinds (inside or out) will reduce glare so you aren’t squinting.
If you need another room, you need to have an extension. This will cost you a lot more and take a lot more time to build.