They're ball park figures.
I'm using 1,600 pounds for the tree as an extremely conservative estimate without branches or foliage taken into account. A tree taller than a man and as big around as a man, is going to conservatively weigh between fifteen hundred and two thousand or more pounds depending on the wood Another redditor on this thread guessed the tree as a magnolia from the foliage and estimated roughly 1,600 pounds (35 pounds per cubic meter) without foliage or branches taken into account. As magnolia is much less dense than oak or ash, this is more or less a bare minimum for how much he is lifting.
As for the statue, it's about twice the height of Cap, so that's about 12 feet. Considering that a man sized marble statue (ie the statue of David) weighs upwards of 10000 pounds and a man sized granite statue is even heavier, 2000 pounds is a very, very, VERY conservative estimate and it's almost certain that it is more.
Yes, they are inexact figures but they do give us an idea of what he is capable of and at the bare minimum possible figures using the lightest possible materials for those items, these feats eclipse the lifting strength displayed by MCU Cap by a significant margin.
The motorcycle feat is inexact as well. That motorcycle could weigh anywhere from 600 lbs to 1000 lbs and those women could weigh anywhere from 100 pounds to 135 (with 135 being a fairly generous estimate considering Ronda Rousey, a much larger and more muscular woman fights at 135).
Those feats are all for 616 Captain America. The tank slicing feat is from Captain America: Living Legend, the truck feat was from Captain America 21-26 by Robert Morales and Chris Bachalo in 2003. The missile feat was from Leifeld's run. The helicopter feat was from Ed Brubaker's Super Soldier miniseries.
I think you're operating on a fundamental misunderstanding of 616 Captain America. As I've mentioned before, he's NOT peak human in the same way guys like Daredevil, Winter Soldier, Moon Knight, Punisher, etc are. He's consistently been shown to be above Marvel peak humans, being much faster and stronger than them. Writers have identified him as "the peak of human potential" and "the next step in human evolution".
Essentially, this means that he's the furthest human biology can be pushed from an evolutionary standpoint while still being considered human. He's not what humans are capable of NOW, he represents what humans MIGHT be capable of in a thousand years.
He's more superhuman than MCU Cap. But MCU Cap could very well get closer to 616 Cap's level in the next few movies. As of now, he's not quite there yet.