Not really, with a little discipline it can work for the vast majority of scenarios. 90% of my flights are backpack only and that includes travel where I needed to be dressed formally and travel with my SO. The only scenarios where it's actually necessary I see is if you need health equipment (which most people don't), if you have toddlers (which I'd argue you shouldn't be flying with anyways), and if you are moving a lot of stuff (where paying for luggage is still cheaper than shipping in many cases).

It just requires a little planning which I think most people my generation and younger are getting used to.