I think "when I get to this store" is still a time. Android used to be able to handle reminding you "when" you got to a place, but I guess they dropped that feature. So IMO this is on the assistant for not doing what it used to do.
It's a time, but it's an unspecified one. It very specifically stated "say what time you want your reminder" after a location was given, indicating that doing it by location wasn't an option. The user wasn't paying enough attention.
That's not a time, that's an event. The event can happen at a specific time, but you only know that time after the fact. So you want the assistant to react to an event, which it apparently doesn't support.
Though last time I tried assistant responded "I'm sorry I can't set location based reminders anymore". Either they've removed that warning, or this image is over a year old...
turns out that a lot of the time the best solution is just having a dude spend an afternoon hardcoding common interactions, so you know it works and how it works
Sure, they've invested a lot, but frankly, that doesn't mean they've integrated any of it into assistant.
I haven't seen any change in what assistant can do for years, it's good for controlling your Google connected smart home things, asking fairly basic Google queries (the kind of stuff that will prompt a dedicated reply from Google search - like, "what's 5 times 5", or "how tall is mount Everest"), and..... end of list.
Pretty much anything else it can/could do, it either doesn't do, or it does so poorly that it might as well be incapable of it. I used to play a riddle game on my Google homes, which was quite good, it involved being asked a riddle, and it would wait for you to answer, then evaluate your answer to see if you were right, and provide appropriate feedback about that. Like all good things, the riddle game has gone away. I can't seem to give my Google assistant a prompt that will cause it to work. There's other games, sure, but the little riddle one had a little story to it and it was rather enjoyable. When you got to the end, it said something about the story that it would be expanded later (the story was always the same)... and now here we are. No riddle game.
The other stuff I know it can do is to prompt bedtime stories (good for all you parents out there), and play trivia games... with multiple participants even.
For actually useful stuff, like setting reminders, it's not great. The reminders don't really work, they don't tie into your phone... There's just a whole host of issues with it. Even the voice identification stuff is pretty much garbage.... Even if it recognizes your voice, you're basically screwed either way, because you're not getting access to much more data than you would without it.
In OP's case, I'm not sure it understands the location, or location based alerting is off.... Since it would need to coordinate that with your phone. Which isn't something that works with Google in my experience; I have a pixel and I've never gotten an alert or reminder to work from my assistant to my phone. The assistant stuff is largely built around the idea of the Google (now nest) home speakers. So functionality sucks across the board.
Honestly, the AI/LLM stuff coming out with chatGPT and others is only really exciting to me if it pairs into something like Google assistant. I can ask Gemini some extremely complex questions and get good answers, far better than assistants "here's a result from the web" garbage. I've briefly tried both chatGPT and Gemini, and they both do a pretty good job. Pairing that up with a speech to text system (of which, Google's isn't half bad), and a good natural language text to speech system, would make it very useful. Tying that into the existing functions of assistant would be great; and it would be even better if that functionality can be extended into your apps on your phone (or at least those synced to your phone, like text chatting apps: eg: the app formerly known as hangouts, Facebook Messenger, WhatsApp, etc.). IMO, that would be game changing.
I know of some in the DIY/homebrew communities that have experimented with tying an LLM to a program that can interface with online apps, as well as do speech to text and text to speech, all locally. It's hell to get set up, but the examples I've seen of it have been spectacular. I'm considering setting one up to replace my old Google/nest home units because right now, Google assistant is only really used for turning on and off my hue lights.
Home labbers have proven that it works, but as far as I can see, no commercial entity has pushed that into any consumer products yet. Including Google.
Don't get me wrong, Google's actual AI is great. As good as any other out there that I've tried, but that tech is not present in assistant from what I can tell. It should be.
Has Google assistant improved at all? I swear it came out and it was the best assistant on the market... and then it just never got better. I haven't even had it turned on the last couple of years because it just wasn't useful to me.
Home Assistant is currently working hard on assistants. I've not used it much yet but their text to speech offers so much more than any of the larger companies in just customisation alone, plus it all runs locally.
I have Google Home devices all over but they currently mostly act as a dumb speaker and I just get HA to do all of the heavy lifting. The most Google does is set timers and even that just goes into HA for most of the processing.