This can be a question that can get more complicated if you start asking individual players.
Most players will get new gloves every year through their glove contracts with certain companies.; however, some gloves need to be worked in. I would use my glove two years before I would retire it.
When I would get my new glove to use, that would become a glove I would use in batting practice, play catch etc. to get it broken in for next season.
So, the lifespan would usually last 2 years and I had no emotional ties to my gloves. I wasn’t superstitious with my gloves so parting with them wasn’t too difficult.
Some players nonetheless have such emotional and superstitious ties with their glove they would use it until it falls apart, relacing it season after season when needed.
The lifespan of anybody's glove is merely a guess. Although players tend to get gloves in spring training year after year, they aren’t necessarily using those gloves year to year.
Having a glove ready to go for a pro player is crucial if a glove were to break in game. Playing a game where the velocities of a baseball are moving extremely fast from throwing to balls being hit, the glove can take a beating.
Blown laces, although highly unlikely, are more probable at a higher paced game.
In all my years of playing baseball I have seen a broken glove in a game two times that I know off.
On average, I would say the lifespan of a glove can be as long as 5 years if properly cared for, depending on the position you play.
As an infielder and outfielder, gloves definitely had different lifespans. Infielders gloves take on more wear and tear because they are around the ball much more. Even on a strike out they will play catch.
Sometimes an outfielder can go the whole game without even touching the ball. So, as an infielder using the glove for one year before replacing it wouldn’t be uncommon.
Some players will give a glove away every other year to a local high school player that could benefit from a new glove.
What seems like an old glove to a pro player may seem like shiny gold to a high school player.
Outfielders gloves may be used for multiple years until retirement.
It’s a complicated question to answer, but definitely an interesting one.