I used to love playing long solo improvisations on piano. Sometimes as an intro, but mostly as a standalone, independent piece that would evaporate as it was played.
The fantasy is that people like it, are interested by it, and get swept away. Luckily for me, I was pretty good at it by the time I started studying at the conservatory and received praise from fellow students and peers, but there was always a hint of 'meh' in the air. And I'm positive it's not because they were giving false praise. It was more like a "cool story bro" kind of meh.
The trigger for this was probably a masterclass I had in my second or third year from Tamir Hendelman. On records and live, he's an excellent pianist but plays it relatively safe. But at the masterclass we had a splendid 'lab' session where various crazy things were experimented with. It's been a few years since then so I don't remember it well but I recall he did some weird thing with an ostinato.
Everything that went on during that lab was a great learning experience, but most of it, in hind sight, actually feels irrelevant. It probably has some sort of influence on a sub-consciousness level, but it's very rarely immediately noticeable. The main teacher at the Conservatory I go to is one of the very rare cases where you hear this lab stuff actually get implemented, be it solo or in a band.
And so I come back to my initial thing. Solo improvisations on piano can be some of the most powerful music ever - Keith Jarrett's Kohln Concert is the best sold piano solo music in the world - but it's also the least called for.
As such, I haven't been arsed to play that stuff in the past year or three. When you get to a point where you mostly need to busy yourself with studying material you actually (are going to) use, it's hard to justify setting time aside for what crumbles down to the hobby side of the profession.
It's almost unavoidable though that I will restart it again, as my teacher will insist that I play off the wall things should I go for my master's next year. But then I will likely be learning to play them in a more directed way, so the experience can be used as an intro for a tune with a singer.