Personally I keep my my most important files on multiple external storage.
That is a very wise backup ethic.
I agree that is a wise backup policy and hopefully includes at least one copy stored "off-site". However, that is not the point of BitLocker.
Other than passwords, I personally don't keep anything incriminating or that sensitive on my drives that a bad guy could not glean by rifling through the file cabinet in my office (there's that "physical access" issue again!). Bank accounts, insurance records, 7 years of taxes, my military and Social Security records are all in there. I bet that is a similar scenario for most of us.
IMO, for the vast majority of us, the reason to use BitLocker or similar "drive" encryption program is in the event our drives end up in unfriendly hands - that is "physically" in their possession.
If you are a frequent road warrior and have a laptop with sensitive information, BitLocker may be a wise "additional" layer of security for you.
For me, a bad guy would have to break into my house and steal my computer. And since I feel confident I am not a designated target of any law enforcement agency, state-sponsored spy organization or organized crime syndicate, the most likely reason a bad guy would break into my house would be to steal valuables he can fence to get some quick cash for his next "fix".
While that is possible, I am not worried that will happen. Therefore, I do not use BitLocker or any other drive encryption program.
What I always - as in
EVERY SINGLE TIME do, however, is "wipe" every "functional" hard drive and "secure erase" any SSD I dispose of - no exception, even if I know where it will end up.
And for drives that no longer work, I take no chances and I physically destroy them. I have access to a
hard drive shredder but for those who don't, I recommend drilling at least 3 holes
all the way through the harddrive ~1 inch from the center hub. SSDs are much less robust than hard drives so thoroughly smashing with a hammer is fairly easy. Just make sure each memory chip is smashed too.