Dimmer on LED Downlight

Replacing one of the switches with a dimmer should work, using two would have the two dimmers in series when the lights are on, not sure it would work and even if it did, you'd be messing with both dimmers the whole time.

You need specific dimmable LEDs and you need a specific type of dimmer switch.

The alternative might be to fit a smart bulb with the current setup, either standalone with its own remote or connected to a Nest or Alexa system.

The dimmer and switch would both turn on and off the light and the brightness would be set by the position of the dimmer, even if you turned it on at the other switch.

I've a pain in my hole replacing led down lights in the house, they're everywhere, a lot to be said for a lightbulb imo!

They should last longer then other type. You must be buying really cheap poor quality ones.