So yeah, something major will have to be broken, or some break-through in computing. The algo will get broken or aliens have this computer that can crack it.

Then of course, they have to be specifically targeting your one address. Is it a legacy address, is it segwit wrapped or native segwit, has it been spent from ... the number to brute force through all that is so astronomically large that even with any technology available today it would take millions of years.

Anything above a couple of decades is practically impossible. Anything that will take longer than a couple of years and it's much more easier to do the $5 wrench attack.

If they want to be covert about it, they would bug everything you have, install cameras everywhere (or access them), invade everything you do.

If you have any attachments at all, they can use that too. You may not be willing to die for your bitcoins, but will you be willing to let someone else you love suffer for it?