Slot machines used to fill casino floors with cabinets over 40 inches tall,...

https://wiki-byte.win/index.php/Why_Do_Old_Slot_Machines_Need_a_Coin_Mechanism%3F

Slot machines used to fill casino floors with cabinets over 40 inches tall, heavy and loud. Now you can play those same games on a phone screen just 6 inches wide. This shift means you can enjoy slots anywhere without the bulky hardware