I think that we are all unsure of the time concept but that the quantum physicists are a little less unsure but aware that the problem is way more vexing than the man in the street understands. Just as German has Technical German I think we have arrived at a similar place where a special vocabulary exists.
Additionally, being unable to understand something does not deny its existence. This humorous clip makes the example:
There is an Amazonian tribe which while having been exposed to "the outside world" remains within their own culture. Their language is non-recursive which Noam Chomsky declares impossible and they cannot count. They have no numbers. Yet numbers exist for sure. The old book One, Two, Three, Infinity illustrates the Hottentots who can count as high as three and then the next is "many". This is quite humorous to us who can count very high. The Hottentots are numerically more sophisticated that the Amazonian tribe, but not by much. The author then goes on to illustrate that there are three infinities known to us. IIRC they are the sum of all numbers, the sum of all points on a plane and the sum of all possible squiggles described on a plane. And at this point we, too, are stuck at three.
In summation I think we are a bit like the Amazonian tribe which cannot count, or in another way, cannot comprehend numbers. That we cannot understand that time is an illusion does not mean it is not true, it means that we cannot understand the concept. And, yes, even the quantum physicists argue about ti, but that is their job. I am informed that this is the old Hegelian Dialectic, a lift from Socrates: thesis > antithesis > synthesis. And so it goes.
With apologies, the "English is my native language" is a steal from the late, wonderful Senator Sam Ervin.