Size

Phones kept getting bigger for me. 

L to R: Samsung Galaxy S23+, Motorola Edge Plus UM 5G (2022), Motorola Moto Z (3rd gen), Motorola Moto X (2nd gen).

The Samsung reverses the trend of them getting bigger and bigger.

Thickness has varied a lot over the years too: 

The Moto X is still my favorite phone for hand feel.  It had football leather backing and it was PERFECT!

Motorola stopped making the X.

I liked the form factor of the Z with a case, but that's the rub.  The four generations of the Z were intended to be used with magnetically attached accessories, which you couldn't attach with the phone encased.

Motorola stopped making the Z. 

The Edge was always just a little too big to me, but a very capable hand-computer.

Honestly, if I could get the battery replaced and the OS updated to current, I'd still be using the Moto X2.  It had an SD card slot and a 3.5mm jack.  When it was new, the battery would last for almost a week.