Why BuJo is so easy to be tailored to you, to create a Bu Jo that works for you!
When certain principles or guidelines of bullet journaling don't work out for you, change them or get rid of them.
If you don't use a tracker collection anymore, ignore it.If you prefer weekly reviews, start a weekly log. If you prefer a quarterly review, start one. If you want to keep stuff in other notebooks, do so. Just try to reference them, if they are important to you.
If you don't do it everyday, if you leave out days, so be it. No one, no system "tells" you how to keep a Bujo. No preprinted empty pages glare at you. I tended to use printed calendars a lot, then I had periods of scarcely using them and for the new year I had to get a new one. Frustrating and demotivating if you are not a super regular user.
No such frustrations with your BuJo. You are finishing it when it is full or whenever you feel it is time for a new one. Migrate your entries and off you go. No pressure, no artificial, arbitrary rules. No pressure to conform to a formal standard that is not you.
Some love to keep BuJos with very artful layouts and fine crafted fold outs, great looking sketches. Others (like myself) like to keep a more minimalistic BuJo. Your choice.
BuJo is not a esoteric cult. You are not part of a religion or a specific group. Just some methods you can use or not or create your own.
BuJo is not even a "product". You can use any notebook, or even loose papers. Yes it helps if you bind papers somehow. Keeping the index is much easier when page numbers don't change.
There are people who have come up with binder systems for their BuJo See "How to wuve". Too complicated for me, but I get why such a flexible binder system makes it easier for them.
Nobody forces you to use special notebooks. You can buy notebooks that are maybe a bit easier to use for a bullet journal - if you want. Like the Leuchtturm Bullet Journal Edition 2 only in A5 ;-)
If it is your first time, just take any reasonably empty notebook and start. You will quickly find out what you like and what not. Then just switch to the better format for you whenever you want.
Trying Bu Jo methods and recommendations will help you learn a lot about yourself, your preferences and your habits. As a digital native, it felt strange to use paper notebooks at first. As many others I tried to come up with ways to use a digital BuJo method. Yes, technically not a problem, but the paper based method works and it helps you to get away from the many digital distractions. To reflect and analyse and then to get into a flow, a productive and satisfying way to cope with distractions and find a focus.