At the moment (2013) when OP send 7BTC to Bitstamp, 1 Bitcoin was worth under $100. So at the time, the OP owned that Bitcoin, the value was not so big and certainly does not deserve special checks on how he bought them.
I agree It wasn't of much value back then but with time when BTC reached close to $20k in 2017, and it was allover the news. I don't think anyone who had at least 1 BTC stashed up somewhere in an exchange wouldn't think about a much safer way to keeping it.
Even today, when we are all much more experienced and smarter with notyourkeys story, $700 (how much worth 7BTC in 2013) is not a risky amount, many of us have more than that on exchanges and in addition to risk awareness. $140k is something completely different, I don't think anyone intentionally keeps so much on exchanges for a long period.