Record keeping today is such that very little is lost. Some things are no longer used....like the Saturn heavy lift rockets used to sen man to the moon. But we have the designs and could build a new on if we wanted to.
No, it can not. But that hasn't stopped anyone.
If we had technical advances that were lost over time (that does happen) we would find evidence of it. So far, there is nothing that even points to lost technological advances.
Technology can be lost, yes.
However no, I do not believe were more technologically advanced in the past than now.
However I do believe that society understood the technology of the time in the past better than we do now. Proportionally less and less people understand how anything works and could not create or build any of it if needed to. In the past tech was simpler but more people could make a mock copy of it.
Makes me think of of the books that separated society between the Engineers and labors, those who know things and create and those who do the grunt work.