Hopefully they don’t go out of their way to try to lock you into using their VTT. I’m not a fan of Roll20 myself but as long as they let Demiplane be themselves and keep it mostly open for third party plugins to do their thing, we should be alright in the long run.
I’ve had a lot of success taking the rules that YNAB uses and applying to my own budgeting method. I recommend checking out Actual Budget if you’re capable of self-hosting and want a fancier software instead of a spreadsheet. The rules are key, though; pick a methodology/mindset you agree with and stick with it.