I thought this was a VTOL aircraft so runway length should not be such an issue.

The article references the F-35A which is a conventional take off and landing aircraft (CTOL). The F-35B is the short take off and vertical landing (STOVL) variant. The F-35B belongs to the marines is capable of using extremely short and improvised runways and this has been part of its operational concept for quite a while[1]. For an expeditionary force that kind of thing is important.

The F-35A is a bit different in that its a normal air force fighter. This is just proving that if push comes to shove it can be operated out of improvised bases.

[1]https://www.thedrive.com/the-war-zone/f-35b-just-touched-dow...

The article references the F-35A which is the conventional take-off/landing variant whereas the VTOL variant is the F-35B.

VTOL takeoff usually reduces payload vs a more normal takeoff.

The F-35A variant doesn't do VTOL.

How clean does a runway have to be for an F-35 to take-off from it? I remember a lot of internet grief over the idea of shipping American fighters to Ukraine, on the grounds that the F-16 and other American fighters were designed only for pristine runways. Low air intakes of the sort Americans favor would ingest debris that would damage the engines, so runways have to be absolutely clear. The MiG-29, on the other hand, has auxiliary air intakes above the wing for taking off on a poorly maintained airstrip. So, does the F-35 need specially cleaned highways?

FOD is something to avoid when operating aircraft, everywhere. Meaning clean is clean enough, and if it isn't an emergency landing strips are prepared (basic maintenance, personal facilities, fuel...)

Regarding Ukraine, if it is internet grief, it is fair to assume it is wrong.

And besides, F-16s have operated from Ukrainian airbases before the war in joint exercises. It's not as if US aircraft are fragile snowflakes.

Well, Finland has been landing and taking off F-18s on these road bases for almost 30 years now.