The post above was about the latency of random access to a file, not about the duration of a restoring operation.
The tapes have the fastest sequential transfer speed of any alternative, so the restoring duration should be better than from anything else, if the restoring software plans correctly the sequence of retrievals.
It is true that if the backup software is not clever, you could waste a lot of time to determine what you must restore and where is it. However, this has nothing to do with the tapes, the same can happen with backup on HDDs if the backup software is equally bad.
I am not sure what you mean by having lots of more tapes than reader, as that is the point of tape storage and the cause of it low cost per terabyte.
The only way that I could understand that phrase as a disadvantage for tapes is that when you would need to read as fast as possible e.g. 300 TB with one reader, that would need 10 days, but if the 300 TB were stored on 25 HDDs and you would also have 25 spare computers and some technicians that could open the computers and connect the HDDs inside them and you would also have an 100 Gb/s Ethernet network from those computers to the destination of those 300 TB, then yes, you could read the 300 TB 12 times faster that with a single tape reader.
However, such circumstances seem too unbelievable. For such a huge organization it would be more realistic to buy immediately e.g. 3 more readers to reduce the reading time from 10 days to 2.5 days.
On the other hand, if the 25 HDDs would have been located from the beginning inside a backup system, then that system would have had a price with at least 5 digits, far higher than the cost of a tape backup system, and unless it would have been connected by 100 Gb/s or at least 25 Gb/s Ethernet, its speed could not have been much higher than that of a single tape drive.