>>305837Blu-rays are better for archival purposes if you want to leave behind recordings of yourself for people to find in the future or your relatives.
Alternatively there are archival DVDs too, since a bluray burner is quite expensive (150-200€~) if you don't already have one and those wanting to check them will need a player as well.
Maybe get 1 hard drive 1 SSD and blu-rays/dvds as a third option. What is your plan for this? Could help better if we knew what the purpose is.
If it's just to leave something to look back at for immediate family then as described, perhaps some photographs.
If you want to have it accessible to randos in 100 years then HDDs will last longer. They don't lose data while not powered like SSDs. Forget thumbdrives or SD cards though.
For DVDs and Blu-rays the rot you describe is theoretical for the most part unless stored in humid places or direct sunlight.
Who will actually care though aside from immediate family and how often will they look at those really?
Don't get bent out of shape over it I think. Remember you probably never met your great grandparents let alone know more about them than some random strangers.
Nobody will care in 2 generations and everything you could leave behind will fade either way.
I'd say get the treatment either way if it helps live longer. For what it's worth and how things are looking, it's going to get grim for most of us in 2-3 years time.
I wish you the best of luck.
As for the rest, it really depends. Without context I have nothing much to offer aside from the obvious. Make sure you pass on any expensive stuff you might own like a house or car while still alive to prevent headaches for relatives.
You can also set up access to your bank account in a way that they'll be able to use the funds while your death is being processed instead of it being frozen.
This way you could pay for your funeral if you care for that.
Hope you make it.