@ebveloz I still nurse my almost-2.5yo to sleep most nights. Remainder of the time she cuddles to sleep with dad or falls asleep on drives. She sleeps through the night 90% of the time. The remaining 10% is usually due to some obvious physical issue like being sick, room temperature being too hot or cold, a loud noise from the neighbours, etc. If it’s not illness, then solving the physical problem and giving her some backrubs helps her to go back to sleep. When sick she needs more TLC for a night or rarely two, but then is back to sleeping through (even while still sick).
We never sleep trained because even though we wanted to since about 5mo, we couldn’t quite agree on the best method or on whether to hire a sleep consultant (due to cost). Then at 7mo kiddo suddenly discovered belly sleeping and consistently doing 6h stretches, so we decided to wait and see. There were a lot of “regressions”, split nights, illness, teething, etc but we could see her sleep getting better every month, so we just kept trying to create good routines and hoping for the best. By 16mo kiddo was probably sleeping through the night (~10h continuously) 50% of the time, and the other 50% with anywhere from 1-3 wakeups. But just before 2yo she started consistently sleeping through unless disrupted by something external, like I described above. Even changing to a toddler bed and now to a full size bed didn’t disrupt the sleeping through. We just sometimes find her in a random spot on the floor but she never woke us up. And this is with me still nursing to sleep.
So I guess the short answer is - some babies/toddlers grow out of it on their own! Not guaranteed though.