You’re definitely not a new player, but you’ve probably only been playing in the time where gem rewards and release rate of new monsters have been very consistent. I’ve been playing for almost the entire length of the game and have seen the number of gems we get increase more and more. It’s enormous compared to the early days of the game.
I think we get about 8x as many gems, the monsters we want are mythics (that cost 16x the gems) and the release rate of mythics vs release rate of legendaries in the early years is roughly 0.5x. So overall that works out as it being about as hard as it was in the early days, but we now also get a bunch of legendaries along the way. Of course this ignores guaranteed stuff, boosted rates, etc.
For reference, the number of free monthly gems we can get at the moment is about 700:
As another point of reference, I can tell you I’ve earned roughly 4700 free gems since the start of November (5.5 months). Which is 850 gems per month.
Awakening a mythic costs an average of 2133 gems, ignoring the pity counter which reduces that a bit (ignoring it for simplicity and because you won’t necessarily hatch until pity).
So you should be able to awaken a mythic roughly every 3 months on average. If you save and target the “half price” offer at the anniversary you can awaken even more on average. Even as a free player, you can awaken roughly 1/4 of the new mythics that come out. Just my opinion here, but I feel that’s pretty good.
Of course this isn’t the experience of everyone and when you’re playing the game each day you don’t necessarily feel the effect of your progress because it’s done over a long period of time. I can understand why if you’ve been playing in recent years you won’t have seen much change but you could be increasingly aware of the growing number of new things you haven’t been able to get and how lots of other people seem to have big collections of monsters that you can’t afford to own. I think the fact is that if you’re playing for free you’ll always need to pick and choose what you go for and accept there’s going to be a large number of mythics you can’t get.
From my own personal experience, I’ve noticed how in recent years I’ve been getting closer and closer to owning all the legendaries but the number of mythics I don’t have awakened is always increasing. With mythics I’ve been able to manage my expectations and awaken a lot of the ones I want most, with some I eventually decide to skip to prioritise others.