> No part of my life has been harder for not having revolving credit.

Maybe not harder, but one undeniable downside is that you've been paying roughly 2% more for roughly every purchase you've ever made (other than rent or mortgage payments and a few other exceptions) than you would have if you had good credit and used a credit card, due to how the US payments market is structured.

To be clear, I'm not saying that this is a reasonable state of affairs, but it's the reality.

Another issue that comes to mind are rental cars – while there's no real difference in risk protection to merchants (it's not like a credit card on file can magically make a wrecked or never-returned car reappear), many rental car agencies require them; I suspect because they use them as something of a proxy indicator of "generally responsible-enough behavior to have been issued one by an institution also exposed to risk".