At least for very average skaters like myself - in my experience, as you progress past a “basic” trick repertoire, the amount of time you have to spend on board to advance into new trick territory and maintain a larger trick bag increases. This explains part of why so many people quit or become frustrated with skating after getting to a certain skill level (in my opinion). Based on the way you described your “comfort zone”, I think the above is relevant to what you’re asking about.
I think an underrated practice for making “progress” and pushing yourself that isn’t necessarily aimed at additive trick practice or attempting gnarly shit is to take your fundamentals and apply them to harder skate “problems” to figure out. Take a line you like to do and try to land it three times without failing, then run that back a couple of times. Take a trick you have on lock (for me, back 5050s) and do it on something that seems challenging but in reach (right now for me, it’s getting consistent axle stalls and 5050s on larger transition, pool coping, etc). Keep a timer running for a set amount of time and see how many times you can land a set of tricks or lines. I’ve been trying to build up more transition “conditioning” (being able to skate a bowl for 60+ seconds unbroken without totally gassing out) and that has been a really fun way to push myself without putting the focus on tricks at all. This kind of stuff also builds your “XP” and expands the comfort zone, which increases the “base” for more advanced skills, trick progression, etc.