It definitely would not be, regardless of whatever “done correctly” means. Solar noon at exactly 12:00 is only going to happen on a single line of longitude. If you have a timezone centered on that line and exactly 15° (one hour) wide then solar noon will be up to 30 minutes away from 12:00 depending on your east/west position in that timezone.
It was exactly this realization that the numbers were arbitrary and 12:00 didn’t need to be solar noon that led to the creation of timezones in the first place, so that it’s not 4:14 in Norwich while it’s 3:52 in Birmingham and just travelling from city to city doesn’t mean you’re changing your watch constantly and it becomes actually possible to write a sensible rail schedule.
Timezones are already a step toward an arbitrary standard time for the purposes of making communication easier and not needing to change your watch just because you moved around. UTC everywhere would just be another larger step in that already established direction.
This sounds more like the infrastructure in your area just isn’t up to delivering those speeds, regardless what the last mile to the home is.
I promise you Steam’s CDN absolutely can deliver more than 450Mbps. It regularly maxes out my 1.5 Gbps at home, and I have no doubt that it could potentially go even faster than that if I had a better connection.
Like plugging a 10Gbps network switch into a 100Mbps gateway, it sounds like a fast final link to the home is being choked out by poor infrastructure in the region and can’t be fully utilized.