New software as well as software adding new features are being developed on a daily basis. I have to agree with cliffspab as to locking one into a year for 1 product. Being able to test other apps out is a way of learning and investigating other security software.
Most people don't look at the full picture, and they won't get it unless working/having connections with the security vendors. Usually (and i said "usually" because exceptions exists) free product are just paid ones stripped of the most interesting features, less support, less frequent updates (which is a big disadvantage when malware are released every minutes) and turned into a Guinea Pigs platform often used a telemetry miners.
Just look at Windows 10, Home version (full of ads and telemetry) vs Enterprise version where you can disable them without 3rd party tools.
Nothing is free, you may not pay any money but you still pay somehow, often your datas by being turned as telemetry cows.