(obscuring username as not to single anybody out + not negative. just in case someones shy) but this is actually what we did with our journals at first too. we used lighthouse for some time, alongside discord/simplyplural. but with simplyplural being left and not wanting to be as on our phone/computer, we switched to paper.
for people with higher system counts, there are actually really good paperback journal 'packs' you can get at most stationary stores. if buying a 10/15$ journal seems too intimidating, you can get these packs for like, 10 dollars total, and each one only has about 40ish pages.
this way if you have parts that dont front as frequently, you dont have anyone worrying about 'waste' while still providing them their own space. these are just a few examples.
something unexpected this ended up helping with was actually our individual memories too. i noticed some people asking 'how do you journal if you're blurry/have bad memory as a part?' and, well, that's actually why i started doing it. i wanted to remember more than just 'feeling bad' whenever i fronted, so i carry my journal with me and write down basically like, everything.
even just passing thoughts like 'i kind of wish we had beef strips at home for dinner' or 'im really excited for artfight this year'. when you're trying to recover as a system, especially as a part thats been heavily slotted with a lot of 'negative' emotions, its important to give yourself the space to express more than those things. if you only ever remember yourself as being 'angry/bad' then you wont develop much past that, and you start to internalize that shit and really hate yourself.
journaling has been a great outlet for me to vent and draw my own stuff, but it's also given me some dignity and the space to feel like a person outside of just being like. traumatized. i sort of use it as a vault of everything about me, good and bad, important and trivial.
also like, importantly, from both an eco friendly and anticap standpoint, you can really just use stuff you have lying around the house already. i think personalizing your journal is important, but you can also do that without going out and buying 56347875 things. personally i got really into junk journaling alongside writing and drawing, because it gave me a spot to put a lot of the cool stuff that other people would think is trash.