Many say that 888 has a large number of freeroll tournaments, but I think pokerstars has a good number of free tournaments, at least I can play 2-3 tournaments a day at pokerstars. At 888, I can play 1 at most 2 a day.
By far The best freeroll series is Catdschat. You can play on eor several evry day and start a bankroll from zero. As far as sites go for the last couple of monts , Betonline had a huge amount of great freerolls, and freerull satellites to 40, 30 and 150k events. They only have cc events right now , but watch out for when a series starts again.
You are right that celestial freerolls are misplaced from players point, but there are password protected freerolls such as jackpot, vip grinders, no limit, kosei ichinose and some more but I forgot their names
888 seems to have the most freerolls but I prefer the ACR freerolls. ACR used to have more freerolls but now not so much. Pokerstars is the worst for freerolls because they have barely any and when they do its 3000 players or more fighting over $50. Even at 888 the player pool can get quick large in the freerolls. And so I would just prefer to stick to ACR because at least then it's rare to have more than 1500 in a $50 freeroll.
Quantity wise - 888 leads the field, this provider has a number of different freerolls dependent on whether you play real money with them, if you do - you earn tickets for their Sir Prize Giveaway freerolls. Pokerstars are poor, hardly anything, party poker can offer some decent freerolls from time to time and as mentioned before ACR have a lower player field count for their freerolls but dont have as many. GG poker are improving so keep an eye out here.
Easiest way around this? CC members to work on their profile and post count and upgrade themselves to the freeroll club - more freerolls each day across several providers!
At the moment the most freerolls are held at 888, but they are turbo tournaments with 1-2 minute blinds. On PS the blinds are slower, and there in my opinion are the best freerolls where you play poker.