On the ethics of claiming tables when dining out, banana shortages and a crispy rice snack.
You absolutely nailed it with the annoyingly selfish claiming tables scenario. I stubbornly stand in line with my dining companion and refuse their suggestion to nab a table for all the reasons you've outlined. I reckon the cafes will have to take the lead, although it will probably require them to employ a suitably bossy maître d'... Unfortunately I think you're right about it being a wider societal issue - ref. the return to pointless jostling in plane aisles - even a medical emergency on a recent flight didn't stop people trying to push out ahead of the patient & first responders!
The table thing absolutely floods me with anxiety. Your system is an excellent idea, but there's always that one arsehole...(though if the rest of us are following a system, maybe we can collectively shame the dickheads?)
I would like to argue for the opposite: claiming a table before ordering saves the awkward search with your hands full of potential spills and messes! Extreme examples of what people use in other countries to save their tables: phones (South Korea), wallets (Dubai), tissue packets (Singapore), handkerchief (Japan), jackets (Canada & Finland). There was a viral video that went around, and the comment section is gold for finding which countries follow which protocol - https://www.tiktok.com/@matcha_samurai/video/7134518449828613381