This section is another introduction to a list of particular reforms the council bishops called for. See? Not everything was vague about Vatican II:
With the passage of time, however, there have crept into the rites of the sacraments and sacramentals certain features which have rendered their nature and purpose far from clear to the people of today; hence some changes have become necessary to adapt them to the needs of our own times. For this reason the sacred Council decrees as follows concerning their revision.
The point to be made here is that clarity was a higher value for the council bishops than an “organic” connection to a current experience.