Lead acid batteries like to be kept at full charge if possible. Repeated discharging will shorten their life. This is most pronounced with starting batteries. The reason batteries can last so long is partly because modern cars generally start much more easily and the batteries are much heftier than they used to be. For example, the factory fitted battery for my 2 litre Cavalier was 44Ah, whereas our 1.4 Polo has a 60Ah version.

My 2012 Honda Jazz has a 40AH battery. The original lasted 9 years.

Our 2003 Toyota Yaris d4d has a similar life.

It's not about size: it's more design and build quality. Lion Batteries are pants lasting little longer than the 1 year warranty.

I suspect it's more about how they're looked after - a few years back I bought a 2011 Citroen C1 which has a tiny battery, according to the receipts the OE battery had been replaced in 2016 with a Lion battery - that Lion battery was still going strong when I sold the car in 2023, so 7 years old and counting.

I've had an OE Panasonic fail after 18 months so brand name is no real indicator of life/reliability.

Sometimes there appears to be no rhyme or reason. On my 2005 Mazda3 1.6 petrol, all my batteries (from when I essentially bought the car brand new) have lasted 4-5 years (all OEMs) but on a wide variety of usage patterns - sometimes periods of very little use, others a reasonable amount, but never just mainly short trips from cold. No electrical items (I checked for the boot light etc) on all the time by mistake AFAIK.

On the other side, my parent's previous 08 plate Fiesta 1.25 had exactly that sort of usage being mostly an in-town shopping car with occasional trips 8 miles away, a handful of trips per year up to 50 miles and one to Southampton for cruise ship holidays. Their OEM battery lasted from 2008 - around the end of 2020 if I recall.

II suppose it could be that Mazda OEM batteries are either duff or specced to low a capacity, or that Fords are generous and better quality, but given both cars were made during the Ford-Mazda tie-up period, I wouldn't be surprised if they both used the same supplier and re-badged them. Maybe Ford were more conservative with the spec they fitted.

My car currently has a Bosch battery fitted (by the RAC) when the previous one failed just after the end of the first lockdown in 2020. It is about 20-25% higher rated than the OEM and has never (touch wood) given any problems, even in very cold weather like now or when laid up for a while.

Oddly enough, at the first service after it was fitted (5 months) and every one since, the dealership has carried out a battery 'health check' and it 'failed' on condition. Funny, that.