Насколько мне известно, в основном употребляется at the bottom - на дне (и варианты). In the bottom of (см. ссылку) - в глуши. On the bottom shelf - на нижней полке (как часть словосочетания). Или дайте примеры, я не встречала. Разберёмся)

in the bottom - в дне. Например, дырка/трещина в дне
on the bottom - может означать "прилипло/приклеено к дну/донышку снизу"

Actually you can use all three in the same situations (1) physical location: There's a hole at/in/on the bottom of the barrel. (2) rank: He's the worst swimmer on the team - he's always at/in/on the bottom. (3) relative location: The lighter particles floated to the top, and the heavier ones came to rest at/in/on the bottom.

It was super helpful, thanks.

THAT was super helpful)

My pleasure 😇

Why not it?

Ok, if your telling me a story about something that happened to you in the metro, ¿would you say "a strange man walked up to me..." or "the strange man walked up to me..."

a strange man walked up to me

Very good! The same applies to THAT and IT - before you refer to something as IT, you have to call it THAT/THIS/(ITS NAME): A: Did you know that Dan died last week? B: I heard THAT this morning. I can't believe IT.

Thank you! I've taken that into account.

So you could have said "it was super helpful" if I had asked you what you thought of my explanation, because then the explanation would be "activated" so to speak. But since there was no mention of the explanation, your comment with IT seems to come out of nowhere.

Спасибо, Улий!)

👍🏼