I think it's better to create a program or find a program online that will send an email to your love ones regarding about the seed phrase or private key for them to access your bitcoin wallet once something happened to you, like being deceased because of an accident. It's more safe doing that way rather than giving them your private key while you're alive, it's hassle to make a program like that so there's another way.
That's not safe at all.
First of all, you are depending entirely on whichever service you use to do this still functioning well in 10, 20, 50 years' time. If the service disappears in the meantime (which has a high chance of happening), then your email is never sent and your family can never access your coins. You are also depending on the recipient still using the same email address, not having their account locked, the email provider not shutting down, and so on. There are an awful lot of things that can go wrong to mean your email is never delivered.
But even more importantly than that is the security aspect. Using some third party service like this means that they can access whatever information you put in that email. You have no idea how many random strangers might be able to read your instructions about where your seed phrase is hidden, and then use that information to steal your coins. The recipient's email address when combined with the huge amounts of data collected on the average internet user is more than enough to track down an individual and their friends and family.
This methods risks both your coins being stolen and your coins being lost forever. It is not a good method to choose.
There has been a blockchain startup called Digipulse years ago. They failed (of course, as 99% failed) due to bad cash management and they couldn't ultimately pull off the proposed technological development. What they proposed though was a blockchain based solution that frequently pulls information from various sources in regards to a user's activity level. Example: you set a time interval, say every three months, and if your Facebook account has been dead for that long, the vault opens up and triggers a message in whatever form to someone. I get the general idea behind that, but I wonder how the oracle problem can be solved for various methods (Facebook, Email, Telegram, Mobile, etc.) and how many attack vectors there still might remain.
I guess the problem can't be fully solved. Maybe in the distant future. There are so many variables. What if you choose your wife to be the receiving party and she dies along with you in a car crash?
So all these requirements in regards to predefined parameters to be ending up in a bullet-proof solution just seem to be incredibly complicated.
There is also the problem that the right of inheritance goes far beyond than just the closest loved ones in certain cases. Maybe you don't even want the cousin of a cousin to know you own 10,000 BTC at this point
Making sure that that party would reliably receive the keys is probably impossible to be solved without the involved of centralized parties?
It is certainly a hard nut to crack. So I guess it will have to do with the CLTV function in some way, which is also not bad as a potential security backup besides cases of death.
And as you pointed out, time is a huge factor here, although I think that a good solution should also allow for frequent and easy updates to the selected release parameters. If I am not mistaken, the oracle function will always remain of the real issues that need to be resolved.
