Well, for me it's a yes and a no. Being an instrumentalist in an ensemble definitely has helped me in a million ways musically (including composition) and it's doubtful I would have the inspiration to compose without the appreciation and understanding what is means to come together and produce music. In terms of the actual process, I have had little passion for noodling/improvising on a instrument outside of piano (and I can barely play one) - it's probably because solo playing has never appealing to me, and whenever I'm playing alone I almost always envisioning the ensemble sound as I play.
Additionally, the things I want from my music right now barely align with what I've heard and experienced in ensembles (clarinet player, so largely wind bands) and I find myself questioning if what I already know how to write is what I actually want to be writing. I didn't realize it until recently, but I think in some ways being an instrumentalist has impeded my composition as well as helped it, in this respect.
One of my composition teachers once said to me, and I quote, "Good music can be made without any instruments at all." Well, I assure you that there's no point in going down that rabbit hole imo. The more you know about the idiomatic characteristics of instruments and the humans that play them the better composer you will be. Can you imagine a doctor who's only seen a dead body in text books?
100% yes, everything I've written has benefitted from my experience as an instrumentalist.
Trombone less-so than piano, but I find writing music at an instrument to be considerably quicker, more intuitive, and more organic than anything I could produce without it. Hearing physically how tones will react to each other is valuable, regardless of the eventual orchestration.
As a brass player, having an understanding of how instruments work: harmonic series, air, breathing, dynamic control, flexibility and physical limitations is helpful when it comes to orchestration.