Limit is not on "reads", but seeks - its about sled wear. Sony infamously used plastic laser sled skid in first revisions.

https://github.com/JonathanDotCel/psx_clean_laser_mirror

https://psxplanetcodes.tripod.com/repair.htm

Plastic, unlike brass, wears out quickly due to friction. Quickest test was flipping PSX upside down, worn out sled unit would start playing perfectly again in this orientation.

so Yes, there was a rather low seek (move up and down) limit on first units caused by cheap design and inferior manufacturing process.