How much independent time is okay?

My son will be 3 months this Friday, and he’s a pretty independent, but content little guy. Last weekend we had friends over and they brought their 10-month old over and commented on our son’s independence. He was happily playing on his playmat (laughing, kicking, the works) while the adults sat and talked, basically ignoring him, other than watching to make sure he was safe. Our friend mentioned that her little guy was never happy if she left him alone for even a second on his playmat or doing anything else, so she had to hold him or play with/touch him all day when he was young. Now I’m wondering how normal this is?

Every morning I read to my son, dance with him, carry him around the house showing him things and talking to him for a couple of hours until his nap around 10:30 or 11. During that morning awake time I also put him on his playmat for about 30 min while I eat my breakfast and coffee, and he’s perfectly content being alone. Sometimes I’ll put him on his playmat in our bedroom while I shower, put away laundry, clean, etc and he’s perfectly fine with that, too. He’s also totally fine sitting on the couch next to me, staring up at the skylights, without real interaction from me. The only time he absolutely needs to be held and snuggled is in the evenings (starting around 6pm), but other than that he is happy as a clam during the day on his own, as long as I give him 1-2 hours of undivided attention during morning play time. I’m just curious if that is normal or okay? I’m super paranoid about autism or other social disorders because I thought all babies needed to be held constantly.