The number of practice parties would be proportional to the number of people who haven't cleared. The contents we're talking about (creator savage, zurvan ex) are months old, they're somewhat past their "best before date" so it's not weird that there are more farm groups than practice, especially considering they're quite easier than previous savage/ex so many people who are interested in such contents have cleared them. If you're months late then tough luck, there are less people like you so it'll be harder to make a practice group. Is it unfair? Well life is unfair. It's not our fault that we were playing this game 5-ish months ago when creator savage was released. It's also not your fault that you didn't clear those contents soon after their release, but that's just how it works: more people cleared = more farm groups.

Zurvan (and sophia, a9s, a10s) were clearable after few hours of practice for most people, so it's not strange that you see later phase practice parties (or even clear/farm parties) on the day they're released. On the other hand, that doesn't mean there are no practice parties. I saw a lot of practice parties for zurvan/sophia weeks after they were released. Just because some people make farm/clear PF groups a few hours after release doesn't mean you can't make a practice PF group. They're faster than you, so what? Can't they be? They're not obliged to help others who are slower to get up to where they are. Another important thing is that there are many of those clear/farm parties few hours after patch because it's actually clearable quickly so there are enough people to fill those parties, otherwise people wouldn't bother. If someone made an aim to clear PF group for a12s 3 days after patch they're probably trolling or crazy.