Reserved ticket people adjusting with unreserved ticket/ticketless people

Indian from South, traveling to Delhi in Mahabodhi Exp, sleeper class. I am surprised looking at how people adjusting with unreserved ticket folks in their reserved seats, some are giving their upper berths for them to sit. I see 5 people sitting on lower berth and , 3-4 people sitting on side lowers. I am surprised, why are people giving away their comforts to adjust with strangers. If it's a day journey, letting them sit might be fine, but it's an overnight train. Also TTE came and did nothing, he just check ticket and left. Is this a cultural difference? I am curious to know. Am I wrong to feel not to share my seat on a overcrowded train?

Folks on this sub, let me know your opinions.

Ps. Glad! I got the upper berth.

And there is no water in toilets, I am holding my pee since I boarded 🥲