Does light fixture itself impact dimmer compatibility or the bulbs?
Not normally, no.
But ceiling fans, yes.  Because ceiling fans typically insert one of two troublemakers:

A current limiter, to prevent you from over-bulbing the light with 100W incandescent bulbs when they're only approved for 25/40/60W
A &quot;remote control module&quot; so you can use a wireless remote to control fan and light.

Both of them might play badly with LEDs, and both of them may well play badly with dimmers on LED. They were never designed with LED in mind.
And by &quot;LEDs&quot; I mean lightbulb replacement units with LED technology and an Edison screw base, along with an electronic driver to convert 120VAC into DC to run the LED emitters.