"I've been a gamer since the late 80s and have thoroughly enjoyed every gen until the last one"

so, I guess he also played on a fair share of nintendo consoles in the past (?), but even so, I think your comment is a bit to simple and useless if you really want to help him you have to write more than just "ah well play nintendo"

I was in the same spot towards the end of 6th gen, and ended up skipping most of 7th gen. Skyrim and indies got me back into the hobby. A break will do wonders.

If you feel you don't have a lot of time for gaming, stick to shorter, simpler indies for a bit until you feel like jumping into a big pool of a game. Only play games that look fun, not trying to keep up with whatever is new.

Actively hunting trophies can breathe life back intk a game (unless trophy hunting has played a part in burning you out, then turn off trophy notifications and ignore them).

Take a break, do something else for a while. You'll return to gaming one day. Or not, and you wouldn't be any worse for it.

It's true that the golden days of gaming are long gone, but there will always be gems coming out occasionally.

I was like that for a while too for about 2 years. Then I decided to play some old game that i remember being fun. And I became a gamer again.

Had this issue myself. Took something that resembled a break (tough I still played occasionally when bigger titles that interested me, released) of ~2 years. Got my shit together in other aspects of my life, and when I booted up some goodies after a couple of months break, I found out what I truly love, once again It happens. For me it is the same with music, movies and literature... sometimes you need a bit of a break

Most likely, your taste in games has changed but you haven't figured it out how it changed. I suggest experimenting with different genres of games to get a feel for what is fun to you and what's not.

I have played the following:

Sonic Lost World, ZombiU, Super Mario BrosU, Bayonetta 2 and Mario Kart 8.

Not many as of late. 

Play some space quest.

Yoshi's Wooly world will cure all. Also multiplayer in the same house are really fun and Captain Toad treasure tracker is cute fun and charming.

Are you sure you prefer doing other stuff instead of gaming? Are you focused and motivated? Is there any other reason, something that might have happened, that made you lose interest? After you rule out these possible motives, then you can be sure that gaming has lost some flare.

From a few years ago to around 1 year ago, I played mostly sports games, fast and quick sessions and then was too bored for anything else. Then I tried playing indies and my interest got back and then I got a PS4 and have been playing a healthy dose.

The thing is, I still fill extremely bored sometimes. Today I tried Teraway Unfolded and I loved it, but at the same time I was very unexcited with it. The thing is that currently I am not feeling well, and I am at this forum now instead of playing one of the amazing games I have because I am not motivated to do so.

All of this to say that if you like doing something but then you lose interest may be because of inner lack of interest in things in general. If that is not your case, then consider giving it a pause to gaming and maybe you won't get back to it ever again. And that's fine.