For our bikes, "wet" are no good, they are constructed for short bursts of high Amperage, like a starter motor
Was there much else about when our bikes were new and legs were the norm for starting?
Yes I get the short burst high amp bit however I think it's more the case that batteries used to be more reliably built as far percentage of individual battery failures goes but over all decent batteries last much longer now, thinking of my 6 year old Focus still on original battery whereas in the sixties I seem to recall fitting a new battery was a regular thing every couple of years.
First house I remember living in (up to 7 years old) had no electricity, Dad built a "Wireless" housed in a wood vegetable box, it ran on two glass Accumulators (remember them) used them until they where flat then took them into Dumfries to get swapped with charged ones
Later in life during the cold war years I was a volunteer with the Royal Observer Corps, we had underground observation posts lit by NiFe batteries (Nickel Ferrous), these held the full charge for longer periods then went down fast.
So the technology may have changed and left out on a limb a bit