I think it is pretty clear that peaceful CV is harder than a CV where you kill the tourism leaders
Harder, and that's a reason to do it? Domination games when you build no ranged or siege units are also harder, does that mean it's a better way to do it? This forum is kinda weird about things like this. If something is the accepted way to do things, then something that facilitates victory and makes it easier is considered cheating/exploitative, and anything that adds challenge, even circumstantially, is considered ineffective. I've won over 250 games total and over 50 deity games - not to brag, but the reason why I'm still interested in the game after all this time is that I try to do something different each game.
Siam was the hold out in my last deity culture game as well! I don't think I checked to see if taking his cap was enough... I am sure Siam was more sprawling in your game, but 25 turns seems like a long time to wait at that point in the game!
Not that sprawling.. he had capital + 6 cities. The problem was that he was still increasing slowly after all the peaceful approaches were in place - aesthetics finished, all hotels/airports, all dig-sites were excavated and I had majority, internet, winning Igames (1 turn after bulbing internet), faith bought artist-class GW's for theming bonuses, etc. Still increasing slowly. While it was a delay, noone else threatened victory of any kind (had 2/3 of CS's myself and while 2 civs had Apollo, no one had any parts), could have switched to Science myself but wanted to finish what I started. And again, while complete annihilation does remove that civ as a requirement for CV, taking his capital is a 2-fer-1 as his cultural defense drops so much and your tourism output also spikes. Also, just taking his cap gives you a diplomatic slap on the wrist, whereas total annihilation, even if you let someone else get the final blow (btw - lately found success using CSs for this purpose) could lead to the World War vs. you.
Actually for Diplo, I find being at peace with everyone for the last vote is much easier. Liberating CS is pretty much a zero-sum game. If you can recall a civ to life, that is very helpful, but can be done any time.
This is the most efficient way but isn't always an option. An info age CS gives you 2 votes, but having it removed only decreases the votes necessary by 1. I've had games with Genghis and Enrico where there were only 3 out of 12 CS's around at the end of the game and 4 were gone permanently (Venice)- admittedly, this is a scenario where I should have redirected for another VC but, again, wanted to finish what I started.
Taking caps or peaceful. How is that so many? How often have you gotten a peaceful Deity CV?
So many because you can eliminate civs that you KNOW are going to be cultural trouble before they get started, or wait for them to get a few GWs/wonders and then take them out - play completely peacefully - play as if going for a domination win, aggressive throughout, and just win earlier by having a slight tourism focus and hitting a point where the remaining civs are influential - in that regard - prioritizing military techs/tourism techs/science techs (OK, science are always top priority, but there's significantly less of a "right way to tech" than the other VCs.) Point is that sometimes there's minor variance in my diplo and dom games, space games are almost always cut/paste, but each culture game is its own unique entity. For the record, 5 deity culture games peacefully but, in all honesty, with the cop-out civs - Babylon, Korea, France, Brazil, Polynesia.