A custom bike sounds expensive, I really wish there were more east-to-buy prebuilt options.

Yes, it can be expensive, but being obese is expensive. Some people have to go out of their way to buy "big and tall" clothing (at a premium), special beds or chairs, modifications to their car, etc.

Fat people are pretty common, they’re not a rare body shape or disability that should require a custom bike.

Fat people may be common, but heavy-duty bikes are not. For a bike to be stronger, you either have to sacrifice on cost, the weight of the bike, frame materials, or hard-to-find/custom gear.

It becomes a problem when someone is looking for a cheap bike, because none are going to be built to carry an enormous amount of weight.

And I do wish higher weight limit tires were more common, I’m not overweight myself but I sometimes heavily load my electric bike with cargo (and a trailer that pushes down on the rear axle), and occasionally I have problems with spokes breaking already.

They are... for a price. You can get tires and wheels built to handle more weight, but you'd have to pay a premium for them, and be willing to sacrifice their size/weight.

You also have to be realistic of what you're getting. If someone weighing 300lbs wants to get a small folding bike, they aren't going to have much luck with anything.

I fitted new wheels on my MTB turned touring-capable bike, and had to get 36 spokes and very beefy schwalbe tires to accommodate the load. I spent a lot more than someone who doesn't have to worry about carrying weight.

I wish heavy wheels were more standardized for both heavy people and cargo bikes.

They will be. E-cargo bikes in particular have really jumped in popularity, and that will be followed by cargo-specific tires, wheels, and accessories.

But to circle back to the original article. Yes, weight limits and all relevant specs should always be listed and easily available. I personally hate having to dig through stuff to find something as important as torque specs for bolts, as an example.