Um...OK...I think I think about these questions too much.
Why would I not be playing all the games I enjoy now?
Seriously, do you know something I don't know? Is some future event going to prevent me from playing certain games?
I am currently running classic, original Traveller, a game that first came out in 1977. That's 37 years ago. Unless unable to speak, hear, type, think, or otherwise enjoy RPGs, why would I not be playing it 37 years from now?
That number, 20 years, it's bothering that weird anti-math part of my brain that, as a youth, made it impossible to for me to sleep until I knew exactly how many licks it took to get to the tootsie roll center of a tootsie pop.
Forty-four to forty-seven on average by the way. Assuming, of course, that I have an average sized tongue.*
Where was I? Oh yes, so, 20 years ago, what was I running on a regular basis? Let's see...in the period from 1989 to 1994, I was regularly playing:
Ars Magica 1st, 2nd and 3rd Editions, Bushido (FGU), Champions 3rd and 4th Ed., Cyberpunk 2013 and 2020, Ghostbusters (WEG), Mekton I & II, Paranoia, Shadowrun 1st and 2nd Ed., Star Trek (FASA), Star Wars (WEG), Teenagers from Outer Space 1st and 2nd Ed., Toon, Traveller (GDW), and World of Darkness (original WoD, Vampire, Werewolf, Mage).
I was also playing pick-up games, one-shots, convention games and short campaigns irregularly of another dozen games, including homebrews.
Now, let's see what I've been running regularly in the five year period between 2009 and the present year of 2014:
Ars Magica 3rd Edition, Champions 4th Ed., InSpectres (Hacked with Ghostbusters), Mekton II, Mutants and Masterminds 2nd and 3rd Editions (Including DC Adventures), Pendragon 4th Edition, Star Trek (Last Unicorn Games and FASA), Star Wars (WEG), and Traveller (GDW).
Along with playing numerous pick-up games, one-shots, convention games, and short campaigns irregularly of another dozen games including homebrews.
In 20 years? I'm guessing it will look largely the same with a few new ones added and maybe a few fading into the background.
What I do find interesting about the question is how it will be answered by fans of Pathfinder, D&D, and other similar RPGs. Let's say, for example, a person currently enjoys D&D 5th Edition. Will they still be playing that in 20 years? Seems unlikely and that's not a reflection on the quality of the game itself. It's simply the nature of the D&D/Pathfinder business model, creative direction, and fanbase.
My guess is that in 20 years time, that person will be playing D&;D 7.5. Perhaps they'll grow tired of Coca-Cola and try the competitor's Pepsi, Pathfinder 3. You get what I'm saying.
No worries either way. I'll be over in my little corner of the Thought Net, manifesting Star Trek and Superhero ideas to my Holo-Blog. Commune with me over Google Senses won't you?
*Most scientific studies seem to conclude that the number of licks required is considerably higher than the results of my personal research. I can only hypothesize that they are judging the size of a lick differently, are perhaps using less surface area of the tongue or licking implement, and/or aren't continually licking the same spot. There may also be other variables I have not considered.
Additionally, the saliva content could be a major factor. As a youngster, I had a lot of spit.
I never bit lollipops and still don't. I find the very idea akin to nails on a chalkboard.