You only need to make a new will if your circumstances change, If for instance you no longer want someone named in your will to benefit, or if they predecease you.
I suppose if your executor dies before you do, you may need to alter your will or add a codicil.
If anything, property, jewellery etc. is specifically mentioned as going to A or B and you for some reason decide to give it away or sell it, then you do need to revise your will.
It's worth taking into account too, that the older we get, the greater likelihood there is of someone saying we were not in a fit state to make or re-make a will, so if dementia sets in a solicitor may be obliged to refuse to alter or draw up a will.
However, I feel we should probably all think about a power of attorney, especially if one is alone, and make sure that our nearest and dearest know whether we want to be kept on life support or not, and are willing to be organ donors or not