There are many different types & styles of gas fires. Some require a chimney or flue. Then there is balanced flued, power flued & catalytic converter flue- less fires that do not need a chimney or flue at all!
Electric fires have the benefit that the “flames” can be used independently without any heat, so you can still enjoy the cosiness of the flames on dark mild evenings or when the central heating is on, without overheating only a few pence per hour.
Real fires have been with us since the cave man days, but with evolution come efficient fires! Most properties with a class one chimney can have a real subject to HETAS recommendations & building regulations.