Yeah, the old money and time issue of what to do with that one of kind animal that we somehow end up with.
Several years back a local horse trainer discovered a young stallion prospect that was to be sold. So she got one of her clients to buy him and foot the bill. She went on to show this horse to the highest level and he was an important part to get her name in the standings.
Anyway, after the show career was over (as in past the aged events that pay all the money) the owner wanted to show him. You should have heard the outcry! Being that the owner was not a particularly gifted or talented rider. But of course her point was that she was only going to have a horse of that quality once in her life and she paid for him. So she was darn sure going to enjoy him to the best of her ability.
Was it a waste? Ask most trainers and you would have heard a hearty yes!
But he went on to the stallion shed, bred and produced well despite spending the last years in the show ring looking like a lower level non pro horse. But I reckon he really did not care one bit. And the owner had a ball! And after all, is that not what it is all about?
My own experience with both a stallion I owned all of his 24 years and a Border Collie I presently own was similar to the woman in your post. I had a wonderfully talented cowhorse that was trained and shown by my trainer. When he was done showing him I showed him in the Non-Pro classes. My trainer was 100% behind me and very supportive. I was hesitent as I still wanted the horse to attract outside mares. My trainer told me not to worry , with me showing my horse it would demonstate how good minded the horse was!
With my Border Collie I knew I wanted a dog trained up better than I could so she was trained/trialed as a Nursery dog age. When it came time for me to trial her I was hesitent to as I knew I could no where near do as well as my trainer with her, and I did care that my dog looked trained out there on the field. My trainer's answer was--get out there , trial and enjoy your dog. The dog won't care that you are learning. We did share my dog on and off for a few years , and that worked great. My dog got to go to the big trials and I got to trial her in the P/N and learn along the way and move up the levels.
So bottom line, each has to work it out the way that suits themselves, and it is necessary to find the right professionals for the journey.