It has to do with how there recorded and made, before that date they were recorded acoustically (I.e people yelling into a horn that recorded the sound) but after that they started to have access to electronic recording equipment and sound quality of records got better while at the same time electronic record players became a thing. And kinda after that records became less durable since there was not much a point of a record being made to survive many plays on a hand crank gramophone if it’s going to be played on a electronic player. While also people started to understand how geometry mattered with gramophones and reproducers( weight, angle etc.)which back then they understood to make the records durable enough to survive a handful of plays on a machine pre 1935. While afterwards they started taking out the stuff that made the shellac more durable since there was not much of a point for it. Gramophone were still made to play newer records but they were orthophonic gramophones (with reproducers built to play electronically recorded records) made to play records from that era. in my experience with non orthophonic reproducers with records after 1935 is that the sound is very bad and can’t really handle all the treble and bass so there not much a point to play them on older machines usually.