5G for iPhone in cyprus

Apple provides for 5G from their end by having it in the hardware they sell. If you have old hardware then it won't have it. You bought your device for what it had at the time you bought it. It isn't "useless" it is just that technology advances constantly and unless you upgrade your hardware constantly too then there will always be something it is missing. From the other end, it is up to the companies that provide your cellular service to support 5G too. Read all about this by clicking on the link below.

Use 5G with your iPhone - Apple Support

The local semi government telecom provider CYTA VODAFONE has an active 5G network up and running since January 31st 2021. Several Android models including the latest S21 by Samsung is able to access the 5G network since the manufacturers have certified their hardware to the network. “Own a device supporting a 5G network, certified to the Cytamobile-Vodafone 5G network and have the latest software installed.”  is the statement on the telecom providers network. So it is apple dragging their feet with getting their latest 5G capable devices certified to the network. Also they will not communicate how far into the process they are so people have visibility on this and when to expect this to happen. Similar to the ECG function on iwatch which still does not work in Cyprus.

It seems your issue is you have a device capable of 5G but no companies providing that service. Apple doesn't provide telephone service so there isn't anything Apple can do about it. Presumably your device still works with the existing services in your area and as such it isn't "useless".