Why does a sliding glass door drag or stick?
Worn rollers, a dirty or dented track, and a panel that has dropped out of adjustment are the three usual causes. Sand and salt speed all three up, so doors near the Gulf and on lanais are the first to wear.
Rollers are small wheels at the bottom of the panel, and they flatten, crack or seize over years. A door that needs two hands to open is asking for new rollers. Tracks collect sand and dried insects, and a vacuum and a stiff brush help between visits. Aluminum tracks also dent and corrode, which stops even a new roller. Most panels have adjustment screws at the bottom corners that raise or lower the wheels, so a door that has settled can be put back in line. A panel that scrapes the frame at the top is a different symptom from one that drags at the bottom. Describe where it rubs and send a photo of the track.