Games have become more expensive and development time has increased, but still one game plus dlc in this longer than average generation is kind of strange, even shigeru Miyamoto realiases games more often than that.
I wonder if everything is ok at naughty dog I have been worried about them since they started pushing those lesbian themes in their games.
Anyway only time will tell.

Naughty Dog released TLOU in June 2013, developed an expansion with Left Behind in february 2014, canceled the Uncharted 4 version of Amy Hening in 2014, she leaves with the codirector and Bruce Straley and Neil Druckmann took over... a lot of crunch, a lot of pressure releasing Uncharted 4 in May 2016 with around 2 years of development. Bruce Straley leaves Naughty Dog, first sabbath then leaves officially.
Expansion is in development with Lost Legacy, releasing in August of 2017.

When we look at the problematic break up of the two project rhythm in 2014 and we still got a 3 year turn per game that looks still impressive.

Games just need more time and Naughty Dog is not the only developer, from Rocksteady to 343i, CD Projekt Red to Sucker Punch. As long as the games will be good in the end I do not care that it takes longer, especially with Open Worlds binding us longer (not Naughty Dog related for now).

And it's not going to get better when the PS5/Scarlett come out, native 4k becomes the norm and people expect bigger, more complex, more realistic experiences that allow for more freedom and player choice.

Uncharted 4, U The Lost Legacy and TLOU2. Plus you know, remasters. They keeping busy and im liking it.

Aren't they about to release Ghost of Tsushima?

Still no date on it and it probably won't release until 2020, more than 6 years after Infamous Second Son

What do you mean ?? They released TLOU Remastered , UC4 , Lost Legacy and TLOU2 is coming soon

Remember that Uncharted 4 had some development issues which ended up with Amy Hennig leaving the studio and Bruce Straley also left, they were two very prominent members of the studio. I wouldn't be shocked if Neil Druckman made a power-play to get complete control

i think it will release on the ps4... and have a rerelease like the original did on the ps5.... hope it comes soon!

I won't surprised if Sony IPs go down the road of game development periods like those for Rockstar games (GTA, RDR) where we have a game per gen in exchange for a game with even crazier details and content.