These things are like everywhere.

Isolate to potted soil/mix?

i consider them ALL a free show of ma nature ...

they are one of her natural decomposers ...

they are attacking something in your soil .. and it usually.. in my experience... buried ... wet.. rotting wood ... which is often the underside of wood mulch... dead roots of removed trees .. etc ...

IMHO ..... they are of no concern to the plants... and they are actually making compost of the wood... i would suggest.. they are NOT competing with the plants ...

i seem to recall you are a bit reserved in touching things.. lol.. but just pull them out of the pot ...

sterilize your potting media prior to use if you wish ... but with them all over the yard.. you arent going to stop spore production .. in all reality ....

fall is big time shroom season for me... especially this year.. with a couple inches of fall rain .... same in spring .... probably because that is when the hidden wood is wet ...

its just not a big deal.. IMHO ...

though a fungus ... do not equate this with a fungus disease ...

ken