I wouldn't consider drafting a will to be harmless. If its done poorly the next of kin could have to deal with a huge headache and potentially months or years of probate proceedings.
One thing I learned, just bite the bullet and re-write the whole fucking will instead of making riders.
Piecing the will together from riders was terrible. Al the clauses fell away everyone got older. The final will could have been 8 pretty clear pages.
The other part that is hard is just knowing all of the things that happen with assets and a passing. Luckily we had another lawyer and financial folks to advise us. It was still a lot and not that easy to find details. This was pre-ai that would have helped walk through his shit.