If you ordered the 5Div (pre clog) and wanted to pay for clog, then you needed to send the camera back to Canon for the upgrade to be installed. My understanding is that a heatsink was added ie hardware. If it was just software then a firmware upgrade would have provided the functionality.
Of course, if it was just software then the firmware upgrade could have just been copied/shared for free.
"Cripple" is a trigger word for Canon users and been used in a very derogatory way by other system users where it was not deserved. Very bigotted!
Clearly market segmentation has meant that different features are available at different pricepoints. Yes, Canon has added new features to lower level camera bodies that could have been added in firmware upgrades to higher level bodies. We should be aware that firmware feature upgrades (not just fixing "phenomenon" ) have been a thing only relatively recently eg R6/R5 release. I believe that Canon now does this to keep bodies relevant in the market for longer rather than new bodies every 2 years.
Ideally, Canon should release firmware upgrades for a new feature across their whole range of bodies (assuming processor/thermal etc can handle it). In reality, Canon would prefer if we upgraded to a new body or bought a second body.
Phone firmware and phone appss are the only other example I can think of that gives away new features for free and virtually independent of hardware after the initial purchase.