Parks and Public Restrooms
Parks should have a mix of benches and picnic tables. If you have picnic tables, you must have trash receptacles, ideally far enough from the tables to be hygienic but not so far as to be inconvenient.
If people eat, they generate trash. If you do not give them a means to dispose of it on site, you either encourage littering or you implicitly are excluding pedestrians.
When people eat, they need a restroom, both to use the toilet and to wash up. If you have toilets, you need sinks with running water.
Motion activated sinks are both more hygienic and prevent people from leaving the water on. Win/win.
Hot water is a nice to have but is not essential. Paper towels and/or hot air hand dryers are also nice to have but not essential. Ditto soap.
But if you have toilets without sinks with running water, you are de facto spreading disease.
I far prefer individual bathrooms to men's and women's bathrooms. This gives greater privacy and eliminates various forms of social friction for a variety of reasons.
Here are a couple that come to mind:
It's trans-friendly. Individual bathrooms eliminate the question of "Which bathroom should I use?" entirely. Your gender or where you are in your transition is irrelevant while not making anyone else uncomfortable.
It's homeless-friendly as well. Giving homeless people opportunities to clean up a little bit in private is not merely "charity" or kindness to them. It protects public health.
Rest assured, I know from long experience that housed people can do things like brush teeth in a public bathroom and not be hassled over it while homeless people have to live in fear of doing the same and being seen by anyone who realizes they are homeless.
Private bathrooms allow homeless people to tend to small details like anyone else might do and they have much greater need to be able to do so in a public bathroom without being banned or suffering other negative consequences for it.
Very remote bathrooms that get serviced infrequently can be kept low cost and low maintenance by having cold water sinks and toilets only. If you want to be slightly more luxurious while still low maintenance, add a hot air hand dryer. (Ideally, motion activated, not too loud, works reliably without excessive wild hand flapping to get it to see you.)
It's nice to have both paper towels and hand dryers because they can be used for different things, but that's definitely luxury territory.
If you need ideas for how to do public bathrooms well, visit a few Walmarts. Most of them have excellent bathrooms and they usually have one or two men's rooms, one or two women's rooms plus a family bathroom -- aka a private, individual bathroom.
Public parks should have water fountains, the kind that provide drinking water (not decorative fountains). All public parks should have at least one fountain, even if it is a very small park.
Rest areas should also have fountains. If you are on BLM land full of rest areas, you should never be in any danger of dying of dehydration, even if you are stranded, on foot with no cell phone signal for miles.
FYI: I have reason to believe that BLM lands full of picnic tables with no trash receptacles and similar "amenities" are seeing relatively little use by the general public and essentially serve as free resources for rafting businesses who know the drill and are prepared to bring what is needed and take all the trash out again.
I see no reason such sites couldn't have vending machines for things like Gatorade and even soap. If people really want soap to wash up with and didn't bring any, sell it to them instead of trying to keep the bathroom fully stocked under difficult conditions.
Surveys and testing (aka trial and error, plus going over the data) could help determine what else might prove popular at such places. From what I gather, modern vending machines can provide enormous information on what is selling well, when things need to be restocked, etc.
It may not have made sense in the past to place vending machines in such remote locations, but it looks extremely workable to me now.