I'm in the same boat as Tristan on this, in that it takes a huge amount of effort to find steady RP in FFXIV. I also have more than 20 years experience, but I kept coming across RPers who flaked out on me, ghosted off, or ended up as once-offs. It took a couple of months (this last time) to find a few people I enjoy RPing with and I'm really happy I kept at it to find them. I still reach out trying to find more people to connect with, but it's not a fast, or easy process like it is in other RP communities.
I know it can be discouraging, and I've honestly cried from the sheer frustration of it, going so far as to quit a few times in the past. This time I decided to dig in because I really enjoy FFXIV as a whole and getting solid RP would be awesome. I've set up a routine of hitting a few events a week my character would attend and working on becoming a regular, while also forcing myself to interact with a new person each time. When folks put up ads here and on discord, I send messages to the ones that share a similar RP style and have characters that read as if they have story potential with mine.
I've tried to pinpoint why the largest RP community across the MMO platform seems to have so many seemingly transient and finicky RPers, but I stopped worrying about it and kept swimming through them. The gems will show themselves to you eventually, I'm learning.
Stick to what you enjoy so that when you do start attracting like-minded players, they're liking you for what you enjoy. I wish you the best of luck and hope you find fun.