Soooooooo:
Accessories (eg sunglasses, rucksacks maybe)
Art
Books
Booze
Cards
Cinema/theatre
Clothes
Club/festival
Coffee
Concerts
Eco (eg ecologi)
Energy (as in bills)
Fitness
Flights
Furniture
Gaming
Health
Holiday (would use this for hotels/Airbnbs as opposed to flights etc)
Home
Household / cleaning
Insurance
Jewellery
Junk food
Music
News
Plants
Politics
Presents
Privacy/security (Eg VPN, malwarebytes )
Pub/bar
Rent
Restaurant
Solidarity/support (eg various patreon and Novara subs, which, side note, would have each transaction split 50/50 across art/solidarity and news/solidarity respectively)
Stationery
Tv/film
Takeaways
Taxi
Tech
Tech service (eg iCloud as opposed to iPhone which would itself be in tech)
TfL
Toiletries
Trains
Uni/work
Water (as in bills)
WiFi
iOS (individual apps)
And four others which I won’t post here today 
Looking through them just now…I could maybe subsume 2/3 into other categories and get by on tags due to the infrequency of transactions, but I split them out because I thought it was important to have a top level view even if there wouldn’t be many transactions (Privacy/security as a prime example of this).
I will one day have a pet, probably a car, maybe even a child. And that’s not to mention that much smaller things in my life could change which would necessitate me wanting to track my spend in some other less obvious categories.
So if there’s no technical reason for the cap, I would really appreciate it being lifted to at least 100 
Edit: feel like I’ve just provided a pretty deep insight into my thinking 