What is the benefit of capping a gas fire?

More and more Landlords are removing or not installing gas fires due to the potential dangers of CO poisoning if the fire is NOT serviced on a regular annual bases, stating that problems can occur even if the fire is annually serviced. For example blocked flue way (chimney) due to falling masonry or birds behind the fire causing you unnecessary expense of removing them. In addition it would be wise to install a CO alarm too if there is a operational fire present...............So do you really want all of this potential hassle!?