Tineszones exist because we have two uses for time
Not really. Time zones exist for 1 reason: it was too difficult for each town to have its own time, especially when it came to train schedules. So, they were organized into zones so that 6pm in Baltimore and 6pm in Philadelphia were the same. But, people were still used to having 12 pm being the time when the sun was at its peak, so NYC was put in a different zone from Los Angeles.
To communicate across wide stretches of the earth, you need a way to know where the sun is wherever the person you’re talking to is
You normally don’t need to know where the sun is, you need to know if it is normal business hours. Or, if it’s a friend, what their schedule is like and if this is a convenient time for them. You can search for the time in that other place and guess that maybe their business hours are 9 AM to 5 PM, but that isn’t always true across companies and especially across cultures. What you really need to know is something like “what are Dimitri’s business hours” which is easier if everyone uses UTC. If you ask “What are Dimitri’s business hours” and you get the answer 8h - 16h EET, now you need to figure out what “EET” means. But, if you get 6h - 14h UTC and you’re also using UTC, there’s no conversion needed.
is the man in Madrid likely asleep if I’m eating lunch?
If that’s what you need to know, what you really need are the current UTC offsets used to describe time zones. Just store those as “sun offsets” relative to cities and nuke the time zone aspect.