My baby boy is 3 months old and feeds for around 10-20mins every 2.5 hours too!
I spoke to breastfeeding lady about this and she said they get really good at getting the milk out so it’s very normal, as same with my LO
Typically after I posted this she fed for 20 minutes 😂
Mine is almost 3 weeks old and she can feed between 5 and 20 minutes in a row. However most of the time she intermittently feeds so each feeding session can last for like an hour on and off my breasts. She usually feeds within a 3 hour window and usually wakes herself up to feed.