no this was not my experience or that of my family in parochial school. I attended for 12 years in the 50s-early 60s and from third grade on had bible study 3 days a week and church history the other two days, in addition to catechism and religion class. I found, upon taking college level scripture courses (at state schools) I had a better grounding in bible basics than most students even those studying for divinity degrees.
My children went to a total of 3 Catholic elementary schools in the 70s-80s and also received a solid orthodox bible education in addition to very good catechesis and faith formation. My grandchildren attend a total of 5 Catholic elementary and high schools and also are getting an excellent faith formation, catechesis, and grounding in scripture. My 5th grader recently gave me a lecture on some bible events, including some typology. These would be in the Michigan-Ohio area, over 5 decades.
I do however have siblings, children and grandchildren who had the advantage of the same education but seem to have learned or retained nothing of what they were given.
religious education textbooks approved by the US bishops, and I am familiar with most if not all the series used in the 80s to the present, almost all include a scripture passage in all or most lessons, and many programs are lectionary-based, as are many sacramental preparation programs. My guess is there are many children who receive huge doses of scripture as part of their RE but fail to make the connection between the textbook, and the “big black book”, possibly because they never see the bible read or consulted in their own homes.