To be fair, I didn't know that the coolant in a Bolt is supposed to be good for 150,000 miles, that's a good bit longer than I figured. I was thinking closer to 90,000 miles, but you're right, the lower service temperature and also less metal surface area will make it last longer in an EV. But in an ICE, exhaust and oil should not be getting into the coolant at all. If it is, any long life coolant is going to need to be changed out immediately while your head gasket is replaced to fix the oil/exhaust leak. One of the major reasons why coolant has a service life is because of corrosion inhibitors present in it that get used up over time.
You're also right that brake pads are going to last longer, on an EV, they barely wear at all. However, there's the brake fluid that will wear out just as fast as on any car. Over time brake fluid picks up humidity, there's no easy way around this. It'll cause the car to potentially lose the brakes if ignored long enough or even rust out brake lines.
Then there's still every single suspension component that a traditional car has. Balljoints and tie rod ends are always going to wear. If you're lucky, your manufacturer might have chosen components with built in grease fittings so that with regular maintenance you can extend the lifespan of those components but that's the exception, not the rule. There's still bearings, shock absorbers, CV joints, motor mounts, and bushings on various things. Every one of those has a finite service life, just because Chevy doesn't list a recommended interval to replace them doesn't mean that they don't need to be inspected and replaced as they wear down.
As for the actual oil comment though, the Bolt isn't direct drive, it has a fixed ratio gearbox with a differential built in. It only has a couple of gears and the differential, but still, they're helical gears and they need the right viscosity oil. Over time, those gears are going to degrade the oil from the shear forces and add contaminants to it. Contaminants are also slowly going to seep in from the vent, you can't completely seal up a gearbox, you need to have a vent on it otherwise running it is going to push oil out of the seals around the axles. As for the recommended intervals you quoted, that's pretty unrealistics and most manufacturers aren't recommending crazy intervals like that.
Here's the maintenance schedule for a Honda: https://techinfo.honda.com/rjanisis/pubs/om/SI9999/SI9999O00...
It doesn't have that high of a service interval but for something like a 2015 Honda Civic it's still just using their regular long life coolant which is supposed to be good for 5 years or 60,000 miles. Brake fluid is something that's pretty much always going to last around 3 to 5 years regardless of manufacturer. And manual transmissions typically have a much more reasonable recommended fluid life of somewhere around 90,000 to 120,000 miles. Some manufacturers are listing some transmissions as having "lifetime" fluid, but there's also identical transmissions with the same fluid in other vehicles where the recommendation is 90 to 120 thousand miles. There's no such thing as "lifetime fluid", every single fluid in any vehicle wears down in use and picks up contaminants, eventually every fluid will need to be replaced. Any manufacturer who tells you otherwise is lying to you.
Do you have a source for some of your claims? Honestly the recommended change interval of 200,000 to 300,000 is higher than I've ever seen and even on stuff like a 2015 VW Jetta you're supposed to change the manual transmission fluid every 40,000 miles. Here's the 2014 Jeep Wrangler service interval for the manual transmission and transfer case: http://www.wranglerforum.com/attachment.php?attachmentid=198...
250,000 miles is much too long for a differential, I'd imagine the drain plug was probably coated in metallic sludge right? I've seen a few drain plugs out of differentials and transmissions that were all treated way better and still be coated in what used to be the gears.