I have been using TGTG for over a year (bought over 200 bags). It is a great way to save some money and try new things. The quality and quantity usually differ depending on what company you buy from. There are in general two kinds of companies, Supermarkets and restaurants:
Supermarkets are the most unpredictable, You will usually get many different things that are about to expire. In my experience, they are usually really good deals (20+€ worth of food for 5€). However, its essentially all stuff that didn't get sold you usually need to buy a bunch of extra stuff to really make full meals, and there might be some stuff you don't like/eat.
The other big category is restaurants/hotels. Here you will usually get between 1 and 2 meals for 5 or 6 euros. Here I essentially try every new one a couple of times and if I like the food will get a TGTG bag from them regularly. Here the big downside is that they might not have any food to give away, whereas supermarkets essentially always have stuff they have to throw away, restaurants might run out and cancel your order (or just not have anything when you arrive). You will of course get your money refunded, but now you need to still find food, at a time when most restaurants have/are about to close. And ofcourse, depending on how picky of an eater you are you might get something you don't like.
The last big problem is that the really good deals sell out incredibly quickly. I know one restaurant that has really good pasta and lasagnas that sells between 5 and 10 TGTG bags per day but always sells out within 60 seconds. So it is sometimes not really feasible to get a bag from the best places.
However, once you know your local market and what bags to get (and which ones aren't worth it). It is an absolutely fantastic way to both save money and eat good food. I regularly get food from restaurants that I would normally only go to on special occasions. And would recommend anyone to install the app and try it out!
I mean... Let's just take your example of "we have a jumper at x and y street". Is it really a good idea to have everyone know that? Do we want "journalists" to drive over their and take pictures of people in crisis (possibly worsening it).
Or let's imagine a car chase, do we really want criminals to know that a spikestrip is set up 2 streets ahead?
Do we want information like warrant and licence checks to be held over unencrypted radio transmitions. Allowing everyone who wants to to listen in and learn about people's criminal histories?
Just to add, I am aware that the whole idea of privacy isn't really a thing in the US, the names and mugshots of arrested people are literally made public in some (all?) states, so you probably don't care about the last point, but the rest still stand, and in lots of countries everyone's privacy is considered a right, including that of (suspected) criminals.