Well I played a game to see what kind of finish time could be achieved. Achieved a completely peaceful science victory on turn 217, when my exoplanet expedition reached a new start system. Played OK, although the game was full of surprises as this was my first play through to the end on the Gathering Storm expansion. I play the New Frontier package, with all expansions activated. Here are the details:
Pericles
Deity
Standard size
Standard speed
Pangea
I cheated a little and chose settings for a wet young world with abundant resources. I wanted plenty of woods/rainforest to chop and plenty of mountains. I rolled a few times to see if I could get a phenomenal start like the ones you see in YouTube with a wonder within a few tiles and so on, but no luck. I settled for a pretty good start where moving just one turn I had one amber, one silk and one ivory within three tiles of city center, and some nice 2/2 tiles that could be worked immediately. On turn 4 or 5 I discovered a culture city state, Mohenho Daro no less, and I knew I had to play that start. Unfortunately the map only had 2 culture (the other one was Ayutthaya, not great) and one science (Hattusa) city state. Such a pity, I think with 2 science city states and one more cultural I could have done sub 200. Maybe.
No religion of course. This is Deity after all. Scout/scout/settler. Early wonder, just Oracle. Divine Spark pantheon for the great people. I got a relic on t14, that was great. I focused on spamming cities as fast as possible and had 9 cities planted by turn 68 and 11 by t100. At that point I felt that I had a 160-170 win based on what I remembered of vainilla. Ha. That was not to be. They have nerfed a number of key things over the last 3 years (like Big Ben), and of course they have added the exoplanet expedition and at least 10 new civics and techs at the end of the tree which I only discovered as I progressed on my game. They have also added a few more new Great Scientists and Great Engineers, which basically makes it really difficult to get to the ones that help with production of space projects on time to make a difference.
Wonders, apart from the Oracle, I had a nice Petra, which became one of my spaceport cities, I also got Angkor Wat and Big Ben. It took 100 turns for me to found my first city on the coast, which delayed a couple of key wonders, The Mausoleum at Halicarnassus and Kilwa Kiswani. That last one is just amazing, and I discovered it in this game, must have been introduced in the last 2 years. Anyway, apart of that I only had Ruhr in my Petra city and Broadway, which I build opportunistically.
I chopped like crazy with Magnus. I build 2 spaceports, one with faith and one hard build. My exoplanet expedition lasted 10 turns. No wars. Everybody friends or allies by t130 or so. Gandhi, Tomyris, Australia, Roosevelt (Bull Moose), Arabia, Gitarja, Gilgamesh, Kongo, Japan, Catherine de Medici (Black Queen), Montezuma. A nice bunch, well behaved in general.
Mistakes. Well I did not know that I did not need 2 space ports. I could have beelined Rocketry a little bit faster and bought the Spaceport with faith and that would have saved me some turns. Maybe 8-10. In fact my whole end game sucks, I had never played this new end game and well, I need to practice it. I may replay the last 50 turns if I manage to overcome my hatred of minimaxing the 16 cities I ended up with. See if I can hit 200.
Luck. Well that relic. Also, I had space to build a lot of cities, and Ok cities at that. That is weird in Deity I think where space is at premium. I sweated and was lucky to get Ruhr built before the AI. I could see Arabia was building it at the same time as I, and until the very last turn I did not know whether I was going to get it or not.
Anyway, fun game. A violent game where you can exploit pillaging would be MUCH faster, but I like the challenge of building a peaceful science victory. I have found no benchmarks on what is a good finish time for peaceful science on Gathering Storm, so I don't know if this is a decent result or not. Which is frustrating, if anybody has any feedback on that, it would be fantastic. Here is a screenshot of the turn when I won.