Intel? Probably not. They're main issue is the current animosity within their own company. Unless a CEO can come in and enforce some order or at least basic civility they're not gonna see much progress. x86 and their troubles with advancing node shrinks are less of a problem than that.
AMD? Maybe. Zen3 puts up a damn good fight against the M1 and still makes the case for x86. If AMD can keep up the pace with IPC we'll see them match step with Apple I think. If not, then they'll be in a position to dump x86 and run ARM or RISC-V APUs similar to the M1.
Others: NVidia and Qualcomm have already announced intentions to bring ARM to laptops and desktops. They smell blood in the water. Samsung can't help copying Apple, so I'd expect them to try their hand eventually, seeing as they own their own fabs. We may see other players join in too, since most companies are fabless anyway, and there's always room at the bottom end for $200 laptops and $100 chromebooks.
Eventually, yeah. Others will catch up with the M1, that's just how technology progresses. Apple's got a solid lead for awhile I think though.
There's the separation of the OS, chips and hardware though which makes coordination harder.
I do not think that Apple will be standing still either.
I would love a product that has something like 20 efficiency cores, basically a device with insane battery life.