I’ll take the bait:

• wireless communications can be and are disrupted in several different ways in a warzone. Targeting cell towers, active jamming, interception of messages are all huge concerns and all are solved with Starlink
• wired communications are useless on frontlines for (I hope) obvious reasons
• Quite a lot of the fighting happens in relatively sparsely populated countryside
• And even if we assume cell range is everywhere on land… there’s none at sea.
• All of it and more is solved by Starlink. While Russians learned how to interfere with it eventually, for some time it was near-invincible comms and still brings huge value.

Buuut… In the end Musk gave UA such a wide access to Starlink because the US and UA authorities paid for it a fat coin and most likely followed the payment with an offer he could not refuse. Until China or Russia eventually launch their own internet constellations, the US has a massive edge over literally anyone else and can grant this edge to anyone without it being controversial. Unlike sending military gear which took a while to become reality and was a delicate diplomatic matter, sending a truckload of receivers with access keys taped on them is basic shopping for UA and just a blip in export statistic for the US