We have seen an extreme slowdown in recent years and I think it will stay like this or continue to get worse in pursuit of making bigger and bigger AAA games.
At the end of the day you need manhours no matter how good the tools are and if the tools are getting and the hardware is getting better then the expecations rise accordingly.
Same as this generation I expect roughly the same amount of AAA games or maybe slightly less. The PS4/Xbox One didn't even have their own GTA game if you think about it, while previous generations had multiple GTA entries.
So this is not a Sony thing, but an industry thing in general. I personally wish they would take a step back and focus less on GIGANTIC AAA open world games which feel empty but mostly serve to make you have a lot of hours invested into them.
Did they develop more quickly when we switched form CD-ROM to faster DVDs? When we switched from DVDs to HDDs installs? No!
If anything, dev times will increase because more power means less restrictions. More freedom for devs to chase their vision. Less things to worry about like "hmm, why don't I pack this room full of little details?! It doesn't matter to me if it takes 2-3 weeks longer!".
I still expect 4-5 years for new AAA exclusives, especially with a new engine. 2-3 years for sequels.