Sort of. The NVA-proper got whupped in every engagement with US troops, only the US's continued refusal to send ground troops past the UN-mandated ceasefire line saved North Vietnam from getting curbed.
That versus Ukraine's conventional forces are actually holding ground, and their 'lightning push' produced real gains they've maintained.
I disagree with that, that border was internationally recognized as being that of North Vietnam. The US pushed the envelope of what Russia and China would accept when they started their bombing of the North. If they had sent troops Russia and China would have intervened, as they said they would (and as China did in Korea).
If you read Max Hastings book 'Vietnam', it makes clear it was that the US completely misunderstood what was happening diplomatically. They assumed North Vietnam was a Russian proxy, in actuality the Russian government was begging the North to make a deal, and the Vietnamese were able to exert enormous pressure on the Soviets (and to a lesser extent the Chinese who the Vietnamese despised) to do what they wanted.
What people forget about the USSR was that there were a lot of people within the communist party that actually believed the bullshit, as far as they were concerned Ho Chi Minh (who wasn't even making decisions anymore) was a revolutionary hero in the vein of Lenin and supporting the 'revolution' was the No 1 priority for communists everywhere despite. So for example when the Soviets deployed a new weapon system, there were immediate and very vocal demands for it to be supplied to the Vietnamese.
If the US invaded North Vietnam, and Brezhnev didn't immediately order a military response, he'd have been gone in hours.
All those US Carriers on Yankee Station, they wouldn't have been there long. Thailand and the Philippines would have noped out of a conflict very quickly so the US would have been stuck trying to fight off entire Chinese and NVA divisions, with Russian Air and Naval support.
Ultimately the South Vietnamese government failed, the war was decided when the US orchestrated Ngo Dinh Diem's murder, and replaced him with a talentless hack.