For insignia collections, you had to make preparations for the event,
such as summoning the HVIP beforehand, empowering its family's dragons for quests,...
Basically, you had to invest your resources in it.
Both P2Ws and F2Ps could finish insignia collections with preparation and investment.
However, resources are finite, so most F2Ps cannot prepare for and complete every single collection.
The good thing about insignia collections, like you have said, is that you could at least get 100 HVIP orbs even if you didn't complete it, which could be used for trading and prepare for a future collection.
Sticker collections are more relaxing.
You don't really have to spend any resources, but everything comes down to your luck. Sure, you have to do races and quests if you want to maximize your odds of completion, but those do not guarantee anything regardless.
So, sticker albums are so luck dependant that nothing is really guaranteed, but as a F2P, you may complete consecutive albums without having to spend any Jokers, if you're lucky enough.
The collective rewards for sticker albums are also better than that of insignia collections.
However, if you cannot complete it, you barely get new VIP orbs for trading or improving your VIP dragons roster. Yes, they do give you VIP orbs in the last two sets, but usually you cannot complete the album due to the rigged stickers in those sets, so those VIP orbs are not guaranteed as well.
In my opinion, insignia collections were more of a slow grind, where you build up your resources to invest them in a great collection, while receiving solid VIP orbs for the ones you cannot complete.
Sticker albums are more hit-or-miss. You either win big without really having to invest anything, or get nothing at all.
Nevertheless, I believe sticker albums have the potential to be even better than insignia collections, if they can address its major problems that are the rigged stickers and the lack of a solid pity/guarantee system.