I'm looking for a knife that doesn't need to be regularly sharpened. The knife is for someone who has damaged wrists, and they find it difficult to have to continuously sharpen their knife.
Ceramic knives will hold their edge 'forever', but are brittle. As long as they don't fall, they should be fine.
I googled "ergonomic ceramic knife" and a number of items popped up.
IF ceramic and/or serrated knives do not work as a solution, here are the points for choosing a steel knife that will need less frequent sharpening.
A good starting point is choosing a knife made from a relatively hard (60-62 HRC) AND high wear resistance steel - VG-10 (not bargain basement grade VG-10 though: there seems to be much that can go wrong in making a knife from that steel), or Aritsugu's A-type steel, are well known to be good choices for that purpose.
The key is who eventually sharpens it (can be another person, maybe a professional) has to sharpen it properly - no wire edge. no overheating. intelligent choice of sharpening angles to match knife and user. advising the user on what to do and do not do with it.
Also, sharpening it when it is new can be advisable: Very few knives come with an optimal edge when they are new.
Alternatively, a knife that integrates well with a sharpening aid made or endorsed by the same manufacturer (Wusthof and Global do offer such) could work - the sharpening by these devices is not ideal but acceptable for some.
Don't believe the marketing - any knife will dull after some use.
But... You don't need to sharpen knives every time! You don't need to shave with your cooking knives. For real cooking work to be done it's enough just to hone (to fine the cutting edge) with sharpening steel. Look at https://www.youtube.com/watch?v=Nd7r-3RGpJA
And best of all: 3-5 strokes is enough.