Age of the tires is a guideline. For the purposes of the safety, there has to be enough tread and there can’t be any cracks in the tread.
This is an area where I’ve butted heads with Snow City. They sold me a certified used bike that had tires with cracks on the sidewalll. When I called them on...
I’ve got 2 - one at work that we use as a height adjustable work bench and one at home that I use with the bike. The one I use at home I upgraded the wheel chock. Not that anything happened, just wanted peace of mind. No complaints.
I just bought a slightly used (less than 20k kms) 2014 Mustang. Never winter driven, still looks brand new inside and out. Picking it up next weekend. I’ll continue with only using it as a summer car and store it in the garage for winters. It’ll make a nice addition to the fleet!