Every few years I use Anki heavily for language stuff (German, more recently Latin and Classical Chinese), up to 90 minutes a day, but I can never keep the workload under control, or my habits change, and give it up. I still benefit from a year of training, but it seems the long-tail of spaced repetition doesn't work for me at all. But so long as I get to the point where I can read or watch TV, the considerable effor…
> I can never keep the workload under control, or my habits change, and give it up.
> to build up a highly personalised system that doesn't need to work for anyone else.
"Anyone else" includes "future you", because humans change over time. A highly personalized system is usually a highly inflexible system.