Yes, of course some of my BTC were lost due to the hard drive crash. I didn't saved any BTC I sold most of them. Also I don't tend to earn much from crypto now.
If there were some addresses that weren't lost by the drive, then you
should be able to sign them, right?
What happened to the coins is irrelevant. As long as we have a tx history and a signed message we know the circulation of BTC.