We had joint bank accounts from the very start of our married life. We had PofA to each other (and our children) from about the age or 50. Our savings (not vast!) were in joint accounts initially, but eventually we put them into separate accounts.
We decided to divide the savings with me having more than him. This was a reasoned decision as it looked probable that he was the most likely to be first to need care of some sort in the future. As it happened we guessed right on that score, so when he needed care, social services could only take into account his savings when assessing him for contributions to the cost. Mine were ignored - indeed they were not even allowed to ask if I had any. This meant that when he died last year I was left with a bit of a cushion to fall back on - all his savings were gone, having been spent on his care, but mine were still intact.
Our joint bank account and PofAs meant that, when he became so ill and when he died, life was very simple for me in terms of finances. I had full access to our current account funds (as it was a joint account), to my savings and also to his, as they were in the form of premium bonds and I had his account number and was able to simply go online and take money from his bonds to pay for his care.
There was no need for probate, as it was all so simple.
If you jointly own a property it is worth finding out whether it is as "tenants in common" or "joint tenants" - if it is the latter then ownership automatically passes to a surviving spouse. I believe things are slightly more complicated if it is the former.
All these things are worth sorting now - I cannot tell you how much difference it made to not have to worry about accessing money when my OH needed care and when he died.
The only delay was over me getting a share of his NHS pension as his widow. He only had a small pension as he had to leave the NHS in his early 40s because of ill health, but I had assumed I was entitled to half of that when he died. And as it turned out that is what happened. But it was an anxious time for me for the first few months as I did not know whether I was to be the beneficiary or not. They would not tell me this and froze his pension initially. This anxiety could have been avoided if we had talked about who he had assigned his pension to after his death. I assumed that it was me, but had to wait a while to have that confirmed. So....it might be worth discussing that now and making sure that you are the assigned beneficiary or you could be a bit on limbo when one dies. It was an anxious moment.