I see LOTS of websites and video series catering to so-called "older" grapplers.
BJJ Over 40
BJJ After 40
40 plus BJJ
OG (Old Guy) grappling (put out by a Lloyd Irvin student who was 36 or something. Annoying shtick to boot)
I'm 60 and a black belt, you young whippersnappers. I didn't start Jiu Jitsu until I was 45. Most of you aren't there yet. I'm betting some of you will have retired before you reach my age.
The only guy who's putting out stuff for me and has any authority to speak on the matter from where I sit is Steve Maxwell. Most of the rest of you claim to know what it's like to train at an "advanced" age when you're about ten years younger than me, or more. Believe me, there are a couple of significant drops in physical prowess you have yet to encounter and have little authority to speak on before you hit your seventh decade.
Old Man Jiu Jitsu get a pass as well. Good T shirts and no adoption of the Dan Faggella business model, to name two pluses.
I'll leave you 40 plus "elder statesmen" of Jiu Jitsu to ponder this.