score:6
Even a few years ago, the hotels we stayed at used credit cards, including for settling restaurant bills and for buying larger souvenirs. These were places that catered mainly to foreigners, being either large or eco-lodge wildlife destinations. The more commercial restaurants were also able to take cards for a meal, as were some other shops.
Cash was definitely necessary back then for smaller and more interesting places, and I would doubt it's completely gone. Getting cash from ATMs took a bit of planning, so it was worth starting with some, and leaving the bigger towns with some.
We didn't use buses and our transfers were pre-paid, as it was mainly a self-drive holiday (petrol stations again took cards).
As I recall, we paid national park admissions in cash, but that doesn't mean they didn't take cards.
We took and used both Colones and US dollars, the latter partly because exchange from GBP is uncommon while USD are ubiquitous.